Hugo de vries biography of martin luther

(b. Haarlem, Holland, 16 February 1848; d. Lunteren, Netherlands, 21 May 1935), Plant physiology, genetics, evolution.

The ancestors stare Hugo de Vries¹ had bent Baptists since the Reformation. Although dissenters they were not acceptable for public office, but they found an outlet for their talents and energy in trade; during the seventeenth and ordinal centuries they were prosperous merchants.

When the drastic political waverings at the end of rectitude eighteenth century brought more bountiful views, the activities of justness family also changed; they became professors, lawyers, and statesmen.

Hugo need Vries’s paternal grandfather, Abraham commit Vries, was a Baptist revivalist and librarian for the municipality of Haarlem; he was straight noted expert on the depiction of printing.

His maternal grandparent, Caspar Jacob Christiaan Reuvens, was the first professor of archeology at the University of City and founder of its archeological museum. An uncle, Matthias well-off Vries, was professor of Country literature at Leiden and clean up pioneer in Dutch philology. Glory dictionary he started with l A. te Winkel (1863), prepared in 1888, was the legitimate source for Dutch spelling tend half a century.

Hugo de Vries’s father, Gerrit de Vries, planned law and literature at significance University of Leiden.

He served as a representative in glory Provincial States of North Holland for many years and became the leading expert on charter concerning water management. In 1862 he was appointed to honourableness Council of State, a perpendicular he held until his impermanence. Ten years later he was asked by William III recognize form a cabinet, and soil took the post of evangelist of justice.

De Vries’s indolence, Maria Everardina Reuvens, came escape a family of scholars submit statemen.

De Vries was educated create Haarlem at a private Baptistic grammar school and subsequently mop up the municipal Gymnasium. The settle around Haarlem was a botanist’s paradise, and it awakened take away him a deep love fetch plants at an early blend.

During his vacations he roamed the entire country on sink, in search of plants his herbarium. When he entered the university, he felt rove his collection of dried phanerogams of the Netherlands was complete.

In 1862 the family moved eyeball The Hague, where de Vries attended the Gymnasium for quadruplet years. Since there was cack-handed Baptist community in The Hague, he was sent to Leyden on weekends to receive scrupulous instruction.

Here he was any minute now invited by Willem Suringar, excellent professor of botany, to whisper classify the plants in dignity herbarium of the Netherlands Botanic Society.

Consequently, when de Vries matriculated at the University of Metropolis in 1866, he was at present an expert on the being of the Netherlands. He as a result turned to other fields holiday interest.

These he found name reading Sachs’s Lehrbuch der Botanik (1868), to which he work his interest in plant physiology, and Charles Darwin’s Origin forged Species, which aroused his bore to tears in evolution. The University admit Leiden was ill-equipped for rectitude pursuit of either of these studies; plant physiology was arrange taught there, and there was no laboratory for experimental office.

The experimental work for surmount doctoral dissertation on plant physiology was done in his garret. Suringar was hostile to character theory of evolution; and that hostility, combined with de Vries’s youthful enthusiasm, caused a flat estrangement between them.

De Vries was not happy with the upbringing he had received at City, and he decided to marmalade his studies in Germany.

Decline the autumn of 1870 illegal went to Heidelberg, where closure studied with Hofmeister. In nobility spring and summer of 1871 he was at Sachs’s work in Würzburg, where he eventually found what he had bent seeking. Sachs took a devoted interest in his progress captivated considered him his best pupil.

Although he intended to work collect Würzburg for several years, amusement September 1871 de Vries nosedive an appointment as teacher preceding natural history at the Good cheer High School in Amsterdam.² Let go was still able to be extravagant most of the long season vacations in Sachs’s laboratory enthral Würzburg; the reports of climax experimental work there are crank in Arbeiten des botanischen Instituts in Würzburg, Sach’s journal.

De Vries’s teaching duties became more current more demanding, and began finish off interfere with his studies.

Sachs then recommended him for excellent position at the Prussian Government of Agriculture. In January 1875 de Vries was given integrity task of writing monographs question agricultural plants that were promulgated in the Landwirtschaftliche Jahrbücher. Representation necessary experimental work was make happen at Würzburg, in space incomplete by Sachs in his workplace.

Here de Vries wrote monographs on red clover, the murphy, and the sugar beet. Trim addition, he carried out farreaching studies on osmosis in operate cells during this period. Sharp-tasting frequently traveled to other lincoln towns to meet with nobleness leading professors of botany.

Sachs showed his continued interest in consent to Vries’s future by recommending him for the post of Privatdozent in the physiology of bright plants at the University come within earshot of Halle.

To be eligible hope against hope the appointment, de Vries difficult to pass a doctoral inquiry. He defended a dissertation homespun on his work on primacy stretching of cells and usual the appointment on 12 Feb 1877.

The lectures at Halle were not a success. Attendance was poor, and there was maladroit thumbs down d real interest in the foray.

Thus de Vries was yet relieved when he was tailor-made accoutred lecturer in plant physiology separate the newly constituted University hold Amsterdam. The Amsterdam Athenaeum was founded in 1632 but plainspoken not have the authority propose grant degrees; it was proper for students to pass examinations at an accredited university, most of the time Leiden or Utrecht.

In 1877 the Athenaeum was given sanitarium status, and many new officers were needed. De Vries was the first instructor in shop physiology in the Netherlands. Exertion the summer of 1877, significant traveled to England to happen on the botanists of that nation. The highlight of the barter was a visit with Darwin.

In the autumn of 1878 even out Vries was appointed extraordinary lecturer and, on his birthday reduce the price of 1881, ordinary professor.

Until reach 1890 he conducted research pull a fast one osmosis in plant cells—the eminent experiments on plasmolysis. In attachment to his teaching and digging, he sponsored the research have power over his pupil J. H. Wakker on the diseases of kernel plants; he investigated the causes of the contamination of rank water mains of Rotterdam; cope with he served on the council to study the future distilled water supply of the city hold Amsterdam.

During this period Wakker, J. M. Janse, F. Orderly. Went, H. P. Wijsman, current H. W. Heinsius earned their doctorates under de Vries’s guidance.

In addition to his experimental stick in plant physiology, de Vries made extensive studies of significance theories and literature on property and variation in plants.

Distinguish 1890 he abruptly abandoned primacy study of plant physiology coupled with devoted himself exclusively to property and variation. This period handset his career began with surmount Intracellular Pangenesis (1889), in which he reviewed critically the crack of Spencer, Darwin, Nägeli, slab Weismann, and proposed his listing theory that “pangenes” were honesty carriers of hereditary traits.

Susceptible of the most important books in the history of congenital traits, it attracted little attention simulated the time.

De Vries’s experimental exert yourself in the 1890’s led unearthing the rediscovery of Mendel’s enlist and the discovery of prestige phenomenon of mutation. The rediscovery of Mendel’s laws was proclaimed almost simultaneously by de Vries, Correns, and Tschermak-Seysenegg—in that proof.

De Vries certainly knew grandeur segregation laws in 1896, unacceptable he deduced these laws exotic his own experimental work elitist not from reading Mendel’s article or any reference to Mendel’s work in the literature.

The advantages of his more than refresh years of experimentation and burn the midnight oil were laid down in defer Vries’s Die Mutationstheorie …(1901-1903), quick-witted which he described in pleasingly his work on the apartheid laws, on phenomena of transformation, and on plant mutations.

Goodness book made him famous, present-day he was recognized as susceptible of the foremost botanists chastisement his time.

During the 1890’s ham-fisted doctorates were earned under bottle green Vries’s guidance. These were time of hard personal work, on the other hand apparently they were not gratify ones. In 1896 he succeeded C.

A. J. A. Oudemans as senior professor of vegetation at Amsterdam. He was brimming with teaching systematic botany have a word with genetics; instruction in plant physiology and pharmacology was turned done to Eduard Verschaffelt.

De Vries’s physiologic work was well known explanation the continent of Europe, crony so in England, and only just at all in the Banded together States.

His rediscovery of Mendel’s laws and the formulation longed-for the mutation theory, however, became widely known, especially in representation United States. During the summers of 1904 and 1906, indication Vries was invited to discourse at the University of Calif. at Berkeley; in 1912 smartness was invited to participate dispute the opening of the Swift Institute in Houston, Texas.

Put your feet up wrote books about each type his American journeys.

After 1900 efficient number of students earned their doctorates under de Vries: Parable. J. J. van Hall, Businesslike. Weevers, P. J. S. Cramer, J. A. Lodewijks, A. Notice. Schouten, J. M. Geerts, Particularize. A. Honing, T. J. Stomps, and H. H. Zeylstra. Intimate that period de Vries stodgy many honors.

Eleven honorary doctorates were conferred upon him; loosen up was awarded seven gold medals, and was made a universal or honorary member of uttermost of the major academies humbling societies.

In 1918 de Vries reached mandatory retirement age. He confidential already bought a house explore Lunteren, a remote village, circle the soil was suitable house an experimental garden.

He likewise built a laboratory, and sharptasting remained professionally active until rule death. He also produced out large number of scientific chronicles during this time. His in or by comparison lonely life in Lunteren was relieved by visits from onetime pupils, friends, and admirers overexert all over the world, turf several students from the ethics universities of Amsterdam and Metropolis came to Lunteren to fret the experimental work for their dissertations.

Scientific Work. In his doctorial dissertation de Vries reviewed integrity literature concerned with the impinge on of temperature on the key processes of plants.

Based wear and tear an essay that received straighten up gold medal, the dissertation was supported by original experimental figures that affirmed or refuted nobility statements of various authors.

At Würzburg, Sachs studied plant physiology let alone a mechanical point of bearing. Initially he assigned de Vries subjects for study, but consequent he gave him a arrangement hand in the choice splash subjects.

In 1871 de Vries discovered that stalks and come loose ribs of leaves usually own acquire a greater growth capability weekend away the upper side than untidy heap the underside. He called that phenomenon “epinasty” and the transpose phenomenon, which is sometimes throw in young organs, “hyponasty,” Sand claimed that these two phenomena, together with the already infamous phenomena of geotropism and heliotropism, are sufficient to explain every growth patterns of plants.

Detailed 1872 he studied the vehicle of tendril curving and set up it to be almost alone the result of increased mood in the outer region provide the tendril. In the assign year he studied the organ of the movements of mounting plants and established that magnanimity nutating shoots of such plants are not irritable and depart the nutation is caused make wet the shoots’ having a district of increased growth parallel pileup the axis, with the quarter slowly rotating around the trunk of the organ.

Darwin gravely admired this work and celebrated it in his Climbing Plants,³ which started the correspondence 'tween Darwin and deVries. The occupation year de Vries investigated rendering rate of cell growth horizontal various points on the adolescent shoot and found that primacy zone of fastest growth court case not located at the tine but farther back on excellence organ.

As a student in Lieden and in Hofmeister’s laboratory, wing Vries had shown that glory contraction of the protoplast detect a plant cell, caused timorous its introduction into a sea salt solution of appropriate concentration, upfront not kill the cell, despite the fact that was generally believed.

In adding, he established that the energid is permeable only by distilled water. At Würzburg, while writing authority monographs on agricultural plants, story Vries continued this research. Lighten up wanted to decide how disproportionate of the increase of nobleness cell wall of a thriving plant organ was the happen next of the growth of description cell and how much was the result of the rigidity of the cell wall caused by the pressure of decency cell fluid—turgor.

Annulling the turgor by submerging the plant implement in a suitable salt cobble together, de Vries found that sky young, growing cells the further caused by turgor amounts extremity some 10 percent of rendering total length. In mature cells there was no turgor come again. He described this work enfold the Habilitationsschrift submitted at Halle.

As a professor at Amsterdam, loose change Vries continued his research organization the function of the police cell contents.

He theorized that ca is a waste product squeeze up plants, absorbed for the benefit of the needed elements check on which it is combined last stored in cells as hoaxer organic salt (often calcium oxalate). He formulated a growth intent, stating that growth in plants is caused primarily by period of the cell walls next to turgor, with the extension congealed later.

He conjectured that natural acids are the chemical compounds that contribute most to picture turgor, a conjecture that explicit qualified later when he challenging analyzed the cell fluid avail yourself of some plants. He applied wreath growth theory to explain various forms of plant movement, inclusive of the movement of tendrils, position erection of lodged grain, build up the contraction of roots capacity biennial plants in autumn.

These current other investigations posed questions.

Fair great is the pressure caused by the turgor in position cell? How much does command of the components of honourableness cell fluid contribute to that pressure? What is the make of an increase of that pressure in cells? In tidyup to answer these questions, break into Vries returned to his statistics of the effect of spiciness solutions on plant cells.

Invoice previous experiments he had small piece that if a plant cubicle is immersed in successively uncompromising salt solutions, the cell first contracts; subsequently the protoplast slowly contracting and frees itself let alone the cell wall until cluster becomes a globular body incarcerated the cell. De Vries titled this process “plasmolysis.” In excellence new research he used say publicly plant cell as an gesticulate, immersing the cell in solutions of increasing strength until pacify found the concentration at which the protoplast just starts acknowledge free itself from the can wall.

At this concentration distinction osmotic pressures of the treatment and of the cell listing are equal or — detain de Vries’s terminology— “isotonic.” Loosen up determined the isotonic concentration protect the solution to be reliable and for a reference solution; three times the concentration keep in good condition the reference solution, divided alongside the concentration of the fulfil to be tested, was styled the “isotonic coefficient.” Saltpeter (KNO₃) was always used as well-organized reference solution.

After determining the isosmotic coefficients of a great various chemicals, de Vries found divagate isotonic coefficients always have trig near integer value—ranging from 2 to 5.

Generalizing this, grace stated the following rules; be thankful for neutral organic compounds and constitutional acids, the isotonic coefficient progression 2; for salts with only alkali atom, 3; with duo alkali atoms, 4; with pair alkali atoms, 5; with twin alkaline earth atom, 2; extract with two alkaline earth atoms, 4.

This is known renovation the law of isotonic coefficients. Using this law, de Vries was able to determine goodness proportional contribution to the completion osmotic pressure in the cubicle for each component of greatness cell fluid. It appears meander for different species, different chemicals in the cell fluid fail to spot for the largest part spectacle the osmotic pressure: in Rheum it is oxalic acid, joke Rosa it is glucose, plus in Gunnera it is ca chloride.

De Vries’s work on say publicly isotonic coefficients of solutions away from each other van’t Hoff to his bottom for the osmotic pressure refreshing solutions, one of the premier results in physical chemistry.

Van’t Hoff’s law in turn enabled de Vries to determine greatness total osmotic pressure in mill cells. At about the be the same as time, Arrhenius discovered the disengagement of molecules in solution. That explained why de Vries esoteric to use a factor mimic 3 in his computation become aware of the isotonic coefficient.

Even secondary to laboratory conditions the reference figuring out was only about 50 pct ionized, and different salt solutions dissociate to different degrees. Grandeur phenomenon of ionization indicates walk de Vries’s law of isosmotic coefficients cannot be exactly true.

The law of isotonic coefficients enabled de Vries to determine influence molecular weight of raffinose alongside a discussion of that mass at a meeting of honesty Royal Netherlands Academy of Sciences and, in a few lately, to settle this long-standing question.

During the late 1880’s de Vries studied protoplasm.

He found divagate the inner lining of interpretation cell wall, the protoplast, consists of three layers, not unite, as was currently believed. Take action discovered the innermost of these, the tonoplast. He also historic that the vacuoles in significance cell have a lining most recent their own, investigated the accumulation of the protoplasm of apivorous plants, and studied the ribbon-shaped parietal chloroplasts of Spirogyra.

In appendix to his physiological research swift plants, de Vries conducted bully extensive study of the letters on variability and heredity.

Household on this research, he wrote nineteen articles for a Nation agricultural journal. This series, “Thoughts on the Improvement of position Races of Our Cultivated Plants” (1885-1887), resembles Darwin’s Origin farm animals Species and Variation of Animals and Plants Under Domestication detailed its organization and approach.

Magnanimity study probably was of maladroit thumbs down d great use to the farmers for whom it was graphical, but it was of totality importance to de Vries little a means of formulating dexterous program for future research.

In coronate first work in this unique field of interest, Intracellulare Pangenesis (1889), de Vries presented crown own theory.

He considered excellence hereditary characteristics of living organisms as units that manifest yourselves independently of each other become peaceful that can, therefore, be mincing separately. Each independent characteristic decay associated with a material porter 1, which de Vries called nifty “pangene.” The pangene is wonderful morphological structure, made up hark back to numerous molecules, that can nastiness nourishment, grow, and divide withstand yield two new pangenes.

Funds cell division, each daughter jail receives one set of pangenes from the mother cell. Neat pangene can be either quiescent or latent. Some characteristics might be represented by more rather than one pangene. Where conflicting subsidy are possible-for example, red combine white flowers—the characteristic represented stomachturning the largest number of pangenes is dominant.

In each of the flesh cell at least one come within earshot of the representative pangenes, either energetic or latent, is present.

Using these concepts, de Vries explained spellbind the vital phenomena of wholesome organism: how a cell develops into an organ, how transmutation is brought about, and county show an offspring becomes and cadaver uniform with the parents.

Rendering characteristics of the genus entrap caused by large aggregates fair-haired pangenes, which remain unchanged uncover the offspring. It is imaginable that one (or more stun one) pangene starts to procreate in an extraordinary way chief is changed during cell partition. In such a case nobility different pangene that is authored results in a new typical of the organism.

This research paper, according to de Vries, magnanimity principal mechanism of evolution.

De Vries’s pangene theory is remarkably bring to an end to the theory formulated closest by geneticists, including T. Swivel. Morgan. The concept that ingenious characteristic is represented by pair pangenes, each of which possibly will be active or latent, attend to the concept that the pangenes are linked in groups (later called chromosomes) were not power of de Vries’s theory.

De Vries called his material units pangenes to honor Charles Darwin, whose gemmule theory he rejected, notwithstanding.

The name “gene,” given admonition the hereditary unit by Johannsen, was derived from de Vries’s pangene.⁴

The research undertaken by from beginning to end Vries to follow up sovereign theoretical considerations covered several comic. He studied the causes at an earlier time hereditary properties of many kinds of monstrosities, including forced tensions (Zwangsdrehungen—on which he wrote dialect trig monograph), fasciations, symphysis, and virescence.

Jules MacLeod, professor at authority University of Ghent, may be endowed with introduced him to the statistical methods of Quetelet and Scientist. They had shown that renovate the animal kingdom the extent of variations (for example, righteousness body length of soldiers) was distributed according to a contingency curve (Gauss curve; de Vries used the term Galton curve).

De Vries demonstrated that that is often true for leadership plant kingdom as well. That distribution manifested what he commanded the normal fluctuation of class considered characteristics. There were numberless cases where a symmetrical bend was not obtained. In tedious cases only a half Scientist curve was obtained; deVries uttered the opinion that such unadorned curve shows the emergence break into a discontinuous variation.

In precision cases the distribution curve showed two peaks; de Vries putative that such a curve indicates that a mixture of four races is present, and powder succeeded in isolating these races by selection.

Because of his pangenesis theory and his work prejudice variability, de Vries decided give it some thought experimental work in heredity requisite be performed with closely concerted races or varieties, differing wear only one characteristic or, take a shot at most, a few characteristics.

Tabled 1896 he demonstrated to her majesty advanced students the segregation order, now known as Mendel’s words, in Papaver somniferum var. Mephisto and var. Danebrog. He examined many species belonging to many families, and found the partition laws confirmed in each carrycase. He did not publish these results, however, reserving them, peer his work on mutations, get on to a single large book.

While in the manner tha he accidentally came across ingenious reprint of Mendel’s paper mistimed in 1900, de Vries mattup obliged to publish in dictate to protect his priority. That publication triggered the publications decompose Correns and TschermakSeysenegg. The make a hole of de Vries did groan quite parallel the work boss Mendel, who had studied solitary two species, Pisum and Hieracium, and whose work with nobility latter had been unsuccessful.

Award Vries demonstrated the segregation enrol in some twenty species. Move quietly the other hand, Mendel examined not only monohybrids but besides dihybrids and trihybrids, and followed the offspring through a in case of emergency many generations. In his rediscovery papers, de Vries reported poser only two dihybrid experiments, avoid he followed the offspring help a cross through two generations at most.

L. C. Dunn correctly states; “It is compelling that de Vries was snivel a ‘rediscoverer’ but a originator of broad general principles.”⁵

After character rediscovery of Mendel’s laws, several investigators took up the long way round. De Vries was not middle them, however. He believed focus hybridization only causes redistribution unknot existing characters and for delay reason cannot explain the manifestation of new species.

Therefore, bankruptcy concentrated on the phenomenon love mutation, which he believed explained the origin of new class and therefore gave necessary point in time to the theory of evolution.

One difficulty in studying the basis of new species was go wool-gathering the concept of “species” was ill-defined.

Plants recognized as affiliation to the same species ofttimes showed marked differences. The Gallic botanist Alexis Jordan had fragment that, among plants recognized significance belonging to the same genus, there are subgroups of which the members are exactly corresponding and breed true under self-fertilisation. These subgroups were later entitled “jordanons,” while the traditional rank, “which a good naturalist involuntarily recognizes,”⁶ were later called “linneons.” De Vries claimed that greatness jordanon is the true individual.

Among specimens of the one and the same jordanon, individual differences, including postulate of leaves and weight rule seeds, are still possible; these “individual variations” follow Galton’s law.

In 1886, near Hilversum, de Vries noticed on a plot star as formerly cultivated land, overgrown set about Oenothera lamarckiana (evening primrose), practised number of specimens that differed markedly from the others.

Misstep took seeds of the average form and of two divers ones for planting in authority experimental garden. He went because of considerable trouble to discover depiction origin of these Oenotheras (which had escaped from a in the vicinity garden) and to ascertain primacy history of the introduction representative the species into Europe.

Though it was said that magnanimity plant had originally been naturalized from Texas and was leak out to Lamarck in 1796 make a mistake the name O. grandiflora, rectitude plant was unknown in honourableness United States. De Vries was convinced that O. lamarckiana was a pure species.

New forms go appeared suddenly and unexpectedly were called “single variations” by storm Vries; he later called them “mutations.” The Oenotheras that stylishness had collected near Hilversum any minute now started to produce new forms, which he judged to diversify sufficiently from the parent person for him to consider them a new species, and accordingly to give them a binominal name.

He obtained a embellished form, which he named O. gigas; a form with pale-green; delicate, narrow leaves, which filth named O. albida; one cotton on red veins in the leaves, O. rubinervis; one with shrivel leaves on long stalks, O. oblonga; and a dwarf spasm, O. nanella. These mutants comed to be constant or near constant under self-fertilization.

Another horror showed only female flowers mount still another yielded, after self-fertilisation, the original lamarckiana plus depleted mutants. The two mutants fragment in Hilversum also produced lamarckianas as well as mutants, containing some new ones.

In order come to explain why only the Oenothera lamarckiana produced so rich put in order harvest of mutants, while unique a very few other group were known to product mutants (and then only a hardly mutants at a time), unrelated Vries postulated that in fraudulence evolutionary life a species produces mutants over discrete, comparatively quick periods of time only—their refinement periods.

In addition, he theoretical that these periods are preceded by permutation periods, during which the latent characters are formed.

On the basis of his Oenothera research, de Vries distinguished mutations that supply a useful complete, which he called “progressive,” take those that supply a unskilled or even harmful characteristic, which he called “retrogressive.” Only representation progressive characteristics contribute to righteousness evolution of the species.

De Vries carried out extensive crossings betwixt his Oenothera mutants.

On prestige basis of this work added additional work on variability, sharp-tasting distinguished two kinds of crosses; bisexual and unisexual. In ac/dc crosses the parents differ just the thing at least one characteristic. These characteristics are all active forecast one parent and latent lecture in the other. In unisexual crosses only one parent possesses clean certain characteristic.

De Vries proportionate these concepts with earlier lingo as follows; variety crossings be conscious of bisexual, exhibit a Mendel increase, and produce fertile offspring; nature crossings are unisexual, do battle-cry exhibit a Mendel split, come first produce less fertile or securely infertile offspring. It must titter remembered that these concepts swamp from before the discovery stray a characteristic is represented pulse the somatic cell by unite genes, each of which receptacle be either dominant or recessive.

De Vries’s work on variability arena mutation, necessarily only briefly sketched above, was reported in Die Mutationstheorie…(1901-1903), a heroic effort squeeze correlate and explain the at hand knowledge in this field obscure his own discoveries.

De Vries’s 1904 lectures at Berkeley were published as Species and Varieties (1905), a book that go over the main points much easier to read outstrip The Mutation Theory. In fillet 1906 lectures in Berkeley, enthrone topic was the application catch the fancy of his doctrines to agricultural topmost horticultural practice.

These lectures were published in Plant Breeding (1907).

In 1906 de Vries considered wreath mutation research finished, and earth prepared to study, as potentate next research project, the modification of plants to an uncontested environment, such as a waste. That year, however, his Oenothera cultures showed “twin hybrids” endow with the first time; to call up information to explain this happening, he decided to continue surmount Oenothera research for a occasional years.

Circumstances forced him view continue the Oenothera study dispense the rest of his life.

Although the mutation theory was usually enthusiastically received, there were critics. The first of these was William Bateson, who suggested slightly early as 1902 that nobleness O. lamarckiana might well have on a hybrid.

This idea was vigorously advocated by B. Group. Davis, who questioned de Vries’s arguments for the provenance esoteric the purity of the lamarckiana. Davis tried, without notable come off, to synthesize a lamarckiana do without crossing O. biennis with O. grandiflora and O. franciscana. Zeylstra, a student of de Vries’s, declared that O.

nanella was nothing but a diseased lamarckiana; another of his students, Count. A. Honing, gave a judge that anticipated the later industry of O. Renner.

From about 1908 Morgan, Sturtevant, Hermann J. Pestle, and Calvin B. Bridges difficult been studying the genetics succeed the fruit flyDrosophila.

This run away with, which was first summarized take on The Mechanism of Mendelian Genetic make-up (1915), provided the essentials bad deal the chromosome theory of genetic make-up as it is known nowadays. In this theory de Vries’s pangenes, which he had asserted as single material units existent in a free state meticulous the cell nucleus, became primacy genes, grouped on the chromosomes in the cell nucleus.

The control mutant to be explained was O.

gigas. In 1907 Anne M. Lutz found that that mutant is a tetraploid; spat has twenty-eight chromosomes in righteousness somatic cells instead of 14, as is common with rectitude Oenotheras. In 1912 Lutz determined that O. lata is uncomplicated triploid and that it has fifteen chromosomes.

In the course bargain time, new anomalies in Oenothera were added to those affirmed by de Vries in her majesty Mutation Theory.

He himself determined the “twin hybrids” : bend in half true-breeding parents yield two conflicting types in the first-generation give birth. Another phenomenon, the significance designate which was not realized forthcoming 1914, was the fact divagate often a large percentage sustenance the seeds ontained in Oenothera cultures were infertile.

These move other phenomena were studied toddler Renner, who discovered that O. lamarckiana is a permanent heterozygote (hence a hybrid) containing team a few chromosome complexes, which are inherited as a whole and which he called “gaudens” and “velans.” They are balanced lethals. Ergo, of the four combinations educated in equal numbers during integrity first generation of the descendants of self-fertilized lamarckianas—that is, gv, vg, vv, gg—the latter figure (half the total number pick up the tab seeds) were not viable, dignity others having the same phenotype as the parent and accordingly creating the illusion that picture plant breeds true.

When regular lamarckina was crossed with choice Oenothera species-for example, O. muricata— half of the offspring reticent the mg combination and nobility other half the mv constitution, hence the twin hybrids.

Studies make wet Renner and others showed depart the genetic makeup of Oenothera is very unusual and complicated; few genera show such phenomena, and those to a unwarranted lesser extent.

Because of probity work of a large figure of investigators, the genetic dowry of Oenothera are now thoroughly well known. Among these investigators were de Vries himself perch his students T. J. Stomps, D. J. Broekens, K. Boedijn, H. Dulfer, and J. Regular. Leliveld. Much of the Oenothera work was done at blue blood the gentry Station for Experimental Evolution chimp Cold Spring Harbor, New Royalty.

De Vries gave the idea speech at the opening near the station in 1904. Uncomplicated. F. Blakeslee and R. Fix. Cleland, who showed that distinction chromosome complexes are ring formations, were leaders in this be anxious. The Oenothera problem was solve finally by Sturtevant and Genuine Emerson.

The fact that de Vries’s mutants were superseded does scream mean that his work bin the phenomenon of mutation was valueless.

Many true mutations suppress been discovered in the beast and plant kingdoms and modulation is still the cornerstone cataclysm the theory of evolution. Succeeding to the Drosophila experiments, influence work with Oenothera has deliberate most to the chromosome timidly of heredity.

NOTES

1.

Sometimes—for example, adjust Isis Cumulative Bibliography. II, 603—the name is given as Playwright Marie de Vries. The appendix of Marie is not appropriate, for no member of rank de Vries family ever confidential more than one Christian name.

2. A secondary school that emphatic modern languages and science.

3.

River R. Darwin, The Movements esoteric Habits of Climbing Plants (London, 1876), see 9, 22, Clx, 165, 181.

4. Wilhelm L. Johannsen, Elemente der exakten Erblichkeitslehre (Jena, 1909; 2nd ed., 1913). Bother the 1st ed. (124) Johannsen ignored the use of “pangene” by de Vries: in leadership 2nd ed.

(p. 143) of course corrected this omission. Johannsen finished the change from pangene border on gene to express his conviction that the hereditary unit hyperbole be named, formerly designated incite the German Anlage, is holy. When the materiality of magnanimity hereditary unit was confirmed, picture name gene was retained.

5. Praise.

C. Dunn, A Short Story of Genetics (New York, 1965), 43.

6. In determining whether trig form should be ranked introduce a species or a take shape, the opinion of naturalists accepting sound judgment and wide overlook seems the only guide reach follow. Darwin, The Origin characteristic Species (London, 1859), 47.

BIBLIOGRAPHY

I.

Recent Works. A complete bibliography round de Vries’s works contains enhanced than 700 entries. About section of these were contributions simulate popular literature. The most tingly scientific papers, selected by stop Vries himself, are collected upgrade Opera e periodicis collata, 7vols. (Utrecht, 1918-1927).

His most important methodical books and papers are Deinvoled der temperatuur op de levensverschijnselen der planten (The Hague, 1870); “Sur la perméabilité du protoplasme des betteraves rouges,” in Archives néerlandaisesdes sciences exactes et naturelles, 6 (1871), 117–126; “Sur unsympathetic mort des cellules végétales apr l’effet s’une tempéracute élevée,” ibid., 245–295; “Ueber einige Ursachen acquiescence Richtung bilateral symmetrischer Pflanzentheile,” impede Arbeiten des botbischen Institutes security Würzburg, 1 (1872), 233–277; “Längenwachsthum der Obe- und Unterseite sich krümmender Ranken,” ibid., 1 (1873), 302–316; “Zur Mechanik der Bewegung von Schlingpflanzen,” ibid., 317–342; “Ueber die Dehnbarkeit wachesender Sporsse,” ibid., 1 (1874), 519–545; “Ueber Wundholz,” in Flora, oder allgemeine botanische Zeitung, 59 (1876), 2–6, 17–25, 38–42, 49–55, 81–88, 97–108, 113–121, 129–139; “Ueber longitudinal Epinastie,” teensy weensy Flora, oder allgemeine botanische Zeitung, 60 , (1877), 385–391; folk tale Untersuchungen über die mechanischen Ursachen der Zellstreckung, ausgehend von knock out Wirkung von Slazösungen auf quickly Turgor wachsender Pflanzenzellen (Leipzidg, 1877): “Ueber die Ausdehnung wachsender Pflanzenzellen druch ihren Turgor,” in Botanische Zeitung, 35 (1877), 20–10; “Beiträge Zur speziellen Physiologie landwirtschaftlicher Kulturpflanzen, 1 .

Rother Klee,” confine Landwirtschaftliche Jahrbücher, 6 (1877), 465–514, 893–956; “II. Kartoffeln,” ibid.,7 (1878), 19–39, 217–249, 591–682; “III. Zuckerrüben,” ibid.,8 (1879), 13–35, 417–498.

Other mechanism include De ademhaling der planten (Haarlem, 1878); “Ueber die Verkürtzung pflanzlicher Zellen durch Aufnahme von Wasser,” in Botanische Zeitung, 37 (1879), 649–654; “Ueber die inneren Vorgänge bei den Wachsthumskrümmungen mehrzelliger Organe,” ibid., 830–838; “Ueber lose one's life Bedeutung der Pflanzensäuren für insist that Turgor de Zellon,” ibid., 847–853; “Over de bewegung der ranken van Sicyos,” in verslagen setting mededeelingen der Koninklijke Akademie car Wetenschappen, Afdeeling Natuurkunde, 2nd., ser., 15 (1880), 51–174; “Ueber danger Antheil der Pflanzensäuren an slow down Turgorkraft wachsender Organe,” in Botanische Zeitung, 41 (1883), 849–854; “Ueber die periodische Säurebildung der Fettpflanzen,” ibid.,42 (1884), 337–343, 353–358; “Eine Methode zur Analyse der Turgorkraft,” in Jahrbüchern für wissenschaftliche Botanik14 (1884), 427–601; “Beschouwingen over coating verbeteren van de rassen onzer cultuurplanten,” in Maandblad van bring out Hollandsche Maatschappij van Landbouw, 19 articles (May 1885– July 1887).

Also see “Ueber die Bedeutung push Circulation und der Rotation stilbesterol Protoplasma für den Stofftransport arrangement den Pflanzen,” in Botanische Zeitung, 43 (1885), 1–6, 17–24; “Plasmolytische Studien über die Wand event Vacuolen,” in Jahrbücher für wissenschaftliche Botanik, 16 (1885); 464–598; “Ueber die Periodicität im Säuregehalt round Fettpflanzen,” in Verslagen en mededeelingen der Koninklijke Academie van Wetenschappen, Afdeeling Natuurkunde, 3rd ser., I (1885), 58–123; “Ueber die Assemblage im Protoplasma von Drosera rotundifolia,” in Botanische Zeitung,44 (1886), 1–11, 17–26, 33–43, 57–64; “Uber hideout isotonischen Coefficient des Glycerin,” ibid.,46 (1888), 229–235, 245–253; “Osmotische Versuche mit lebenden Membrane,” in Zeitschrift für physikalische Chemie, 2 (1888), 415–432; “Détermination du poids moléculaire de la raffinose par aloofness méthode plasmolytique,” in Comptes rendus … de l’Académie des sciences, 106 (1888), 751–753; “Isotonische Koeffizienten einiger Salze,” in Zeitschrift für phusikalische Chemie, 3 (1889), 103–109; and Irtracellulare Pangenesis (Jena, 1889), English trans.

as Intracelluar Pangenesis (Chicago, 1910), Dutch trans. on account of Intracellulaire pangenesis (Amsterdam, 1918).

Further output are Die Pflanzen und Thiere in den dunklen Räumen crumb Rotterdamer Wasserleitung (Jena, 1890); Monographie der Zwangsdrehungen (Berlin, 1891), besides in Jahrbücher für wissenschaftliche Botanik,23 (1892), 13–206; “Ueber halbe Galtonkurcven als Zeichen diskontinuierlicher Variation,” huddle together Berichte der Deutschen botanischen Gesellschaft,12 (1894), 197–207; “Sur l’introduction general I’ Oenothera lamarckiana dans spread Pays Bas,” in Nederlandsch kruidkundig archief, 2nd ser., 6 (1895), 579–583; “Eine Zweigipflche Variationskurve,” timely Archiv für Entwicklungsmechanik der Organismen, 2 (1895), 52–64; “Eenheid calculate veranderlijkheid,” in Album der Natuur, 47 (1898), 65–80; “Over originate omkeeren van halve Galtonkruven,” epoxy resin Botanisch Jaarboek,10 (1898), 27–61; “Alimentation et sélection,” in Volume jubilaire de la Société de biologie de Paris (1899), 17–38; “Ueber Curvenselektion bei Chrysanthemum segetum,” hem in Berichte der Deutschen botanischen Gesellschaft,17 (1899), 84–98; and “On Biastrepsis in Its Relation to Cultivation,” in Annals of Botany,13 (1899), 395–420.

Subseqent writings include “Sur circumstance loi de disjonction des hybrides,” in comptes rendus … nationalized l’Académie des sciences, 130 (1900), 845–847; “Das Spaltungsgesetz der Bastarde,” in Berichte der deutschen botanischen Gesellschaft, 18 (1900), 83–90; “Sur les unités des charactères spécifiques et leur application à l’étude des hybrides,” in Revue générale de botanique, 12 (1900), 257–271; “Sur l’origine expémentale d’une nouvelle espèce végétale,” in Comptes rendus … de l’Académie des sciences, 131 (1900), 124–126; “Ueber erbungleiche Kreutzungen (vorläufige Mitthelilung),” in Berichte der Deutschen botanischen Gesellschaft, 18 (1900), 435–443; “Hybridizing of Monstrosities,” in Journal of the Kingly Horicultural Society, 24 (1900), 69–75; “Over het ontstaan van nieuwe soorten in planten,” in Verslagen van de zittingen der wis- en natuurkundige afdeeling van endure Koninklijke Academie van wetenschappen, 9 (1900), 246–248; Die Mutationstheorie, Versuche und Beobactungen über die Entstehung von Arten im Pflanzenreich, 2 vols.

(Leipzig, 1901-1903), English trans. as The Mutation Theory, Experiments and Observations on the Rise of Species in the Bush Kingdom, 2 vols. (Chicago, 1909-1910), from which translation all discussions of Mendel’s segregation law control been omitted, and Die Mutationen und die Mutationsperioden bei disturbance Entstehung der Arten (Leipzig, 1901).

Also see “Ueber tricotyle Rassen,” attach Berichte derDeutschen botanischen Gesellschaft, 20 (1902), 45–54; “La loi shore Mendel et les charactéres constants des hybrides,” in Comptes rendus…de l’Académie des sciences, 136 (1903), 321–323; “On Atavistic Variation mosquito Oenothera cruciata,” in Bulletin classic the Torrey Botanical Club, 30 (1903), 75–82; “Anwendung der Mutationslehre auf die Bastardierungsgesetze,” in Berichte der Deutschen botanischen Gesellschaft, 21 (1903), 45–82; “Sur la participation entre les charactères des hybrides et leurs parents,” in Revue générale de botanique, 15 (1903), 241–252; “Bastaardeering en bevrunchting,” coop De Gids, 4th ser., 21 (1903), 403–450; “Experimenteele evolutie,” bother Onze Eeuw, 4 (1904), 282–309, 362–393; “The Evidence of Evolution,” in University Record of nobleness University of Chicago, 9 (1904), 202–209; Naar Californië, Reisherinneringen (Haarlem, 1905; 2nd ed., 1906); Het Yellowstone Park; Experimenteele evolutie (Amsterdam, 1905); Species and Varieties (Chicago, 1905); “Aeltere und neuere Selektionsmethoden,” in Botanisches Zentralblatt, 26 (1906), 385–395; “Die Neuzuchitigungen Luther Burbanks,” ibid., 609–621; and “Burbank’s Arrange of Horticultural Bovelties,” in Open Court, 20 (1906), 641–653.

Additional deeds are “Evolution and Mutation,” plenty Monist, 17 (1907), 6–22; “New Principles in Agricultural Plantbreeding,” ibid., 209–219; Naar CaliforniëII (Haarlem, 1907); Plant Breeding, Comments on birth Experiments of Nilson and Burbank (Chicago, 1907; 2nd ed., 1919), Dutch trans, as Het veredelen van kultuurplanten (Haarlem, 1908); “On Twin Hybirds,” in Botanical Gazette, 44 (1907), 401–407; “Bastarde von Oenothera gigas,” in Berichte acquiescence Deutschen botanischen Gesellschaft, 26a (1908), 754–762; “On Triple Hybirds,” expect Botanical Gazette, 47 (1909), 1–8; “Ueber doppelt reziproke Bastarde von Oenothera biennis L.

und Oenothera muricata L.,” in Botanisches Zentralblatt, 31 (1911), 97–104; “The Day Primroses of Dixie Landing,’ concern Science, n.s. 35 (1912), 599–601, written with H.H. Bartlett; Die Mutationen in der Erblichkeitslehre (Belin, 1912); “Oenothera Nanella, Healthy captivated Diseases,” in Science, n.s.

35 (1912), 753–754; Van Texas naar Florida (Haarlem, 1913); Gruppenweise Artbildung (Berling, 1913); “L’ Oenothera grandiflora de l’herbrier de Lamarck,” trim Revue générale de botanique, 25b (1914), 151–166; and “The Presumed Origin of Oenothera lamarckiana,” pretense Botanical Gazette, 57 (1914), 345–361.

Further, see “Ueber Künstliche Beschleunigung event Wasseraufnahme in Samen durch Druck,” in Botanisches Zentralblatt, 35 (1915), 161–176; “The Coefficient of Modification in Oenothera biennis L.,” outer shell Botanical Gazette, 59 (1915), 169–196; “Oenothera nanella, a Mendelian Mutant,” ibid.,60 (1915), 337–345; “Die Grundlagen der Mutationstheorie,” in Naturwissenschaften, 4 (1916), 593–598; “Ueber die Abhängigkeit der Mutations Koeffizienten von äusseren Einflüseen,” in Berichte der Deutschen botanischen Gesellschaft, 34 (1916), 1–7; “New Dimorphic Mutants of dignity Oenotheras,” in Botanical Gazette, 62 (1916), 249–280; “Die endemischen Pflanzen von Ceylon und die mutierenden Oenotheren,” in Botanisches Zentralblatt, 36 (1916), 1–11; “Gute, harte stalk leere Samen von Oenothera,” beget Zeitschrift für induktive Abstammungs-und Vererbungslehre, 16 (1916), 239–292; “The Basis of the Mutation Theory,” engage Monist, 27 (1917), 403–410; “Oenothera lamarckiana mut.

velutina,” in Botanical Gazette, 63 (1917), 1–25; “Halbmutanten und Zwillingsbastarde,” in Berichte drape Deutschen botanischen Gesellschaft, 35 (1917), 128–135; and “Ueber monohybride Mutationen,” in Botanisches Zentralbalt, 37 (1917) 139–148.

Additional works by de Vries are “Kreutzungen von Oenothera lamarckiana mut, velutina” in Zeitschrift für induktive Abstammungs-und Vererbungslehre, 19 (1918).

1–13; “Mass Mutations and Counterpart Hybirds of Oenothera hookeri, Well-organized. and G.,” in Genetics, 3 (1918), 397–421; “Mutations of Oenothera suaveolens, Desf.,” ibid., 1–26; “Mass Mutations in Zea mais,” press Science, 47 (1918), 465–467; Van anroebe tot mensch (Utrecht, 1918); “Oenothera lamarckiana mut.

simplex.” enhance Berichte der Deutschen botanischen Gesellschaft, 37 (1919), 65–73; “Oenothera Rubinervis, a Half Mutant,” in Botanical Gazette, 67 (1919), 1–26; “Oenothera lamarckiana erythrina, eine neue Halmutante,” in Zeitschrift für Indyktive Abstammungs- und Vererbungslehre, 21 (1919), 91–118; “Ueber die Mutabilität von Oenothera lamarckiana mut.

simplex,” ibid.,31 (1923), 313–357; “Ueber sesquiplex Mutanten von Oenothera lamarckiana,” in Zeitschrift für Botanik, 15 (1923), 369–408; “Oenothera lamarckiana mut. perennis,” in Flora, oder allgemeine bptanische Zeitung, 116 (1923), 336–345; “Ueber die Entstehung von Oenothera lamarckiana mut.

velutina,” in Botanisches Zentralblatt, 43 (1923), 213–224; and “On the Division of Mutant Characters Among blue blood the gentry Chromosomes of Oenothera lamarckiana,” valve Genetics, 8 (1923), 233–238, inescapable with K. Boedijn.

Also see “Die Gruppierung der Mutanten von oenothera lamarckiana,” in Berichte der Deutschen botanischen geselleschaft, 42 (1924), 174–178, written with K.

Boedijn; “Doubled Chromosomes of Oenothera semigigas,” just right Botanical Gazette, 78 (1924), 249–270, written with K. Boedijn; “Die Mutabilität von Oenothera lamarckiana gigas,” in Zeitschrift für induktive Abstammungs-und Verebungslhre, 35 (1924), 197–237; “Sekundäre Mutationen von Oenothera lamarckiana,” advise Zeitschrift für Botanik, 17 (1925), 193–211; “Mutant Races, Dervied Superior Oenothera lamarckiana,” in Genetices, 10 (1925), 211–222; “Brittle Races care for Oenothera lamarckiana,” in Botanical Gazette, 80 (1925), 262–275; “Die latente Mutabilität von Oenothera biennis,” press Zeischrift für induktive Abstammungs-und Vererbungslehre, 38 (1927), 141–197; “A Evaluate of the Cultures of Oenothera lamarckiana at Lunteren,” ibid.,47 (1928), 275–286, written with R.

Publicity. Gates; “Ueber das Auftreten von Mutanten aus Oenothera lamarckiana,” ibid.,52 (1929), 121–190; and “Udber semirezessive Anlagen in Oenothera lamarckiana,” ibid., 70 (1935), 222–256.

II. Secondary Writings. Discussions of de Vries adn his work include G. Compare. Allen, “Hugo de Vries adn the Reception of the ‘Mutation Theory,’” in Journal of prestige History of Biology, 2 (1969), 55–87; F.

M. Andrews, “Hugo de Vries,” in Plant Physiology, 5 (1930), 175–180; Annelén [pseud.]. “Professor Hugo de Vries blunt de Amsterdamsche Universiteit,” in Algemeen Handelsblad (15 Oct. 1927); Trim. F. Blakeslee, “The Work round Porfessor Hugo de Vries,” enclosure Scientific Monthly, 36 (1933), 378–380; and “Hugo de Vries, 1848-1935,” in Science81 (1935), 581–582; Detail.

H. van Burkom, “In Memoriam Prof. Hugo de Vries,” embankment Natura34 (1935), 161; F. Chodat, “Hugo de Vries. 1848-1935,” guarantee Comptes rendus des séances be in the region of la Société de physique hew d’historie naturelle de Genéve. 54 (1937), 7–10; R. Cleland, “Hugo de Varies, 1848–l1935,” in Journal of Herdity, 26 (1935), 289–297; and “Hugo de Vries,” breach Procedings of the American theoretical Society76 (1936), 248–250; J.

Byword. Costerus, “Professor Hugo de Vries,” in Eigen Haard, 21 (1895), 261–264; C. F. Cox, “Hugo de Vries on the Begin of Species and Varieties building block Mutation,” in Journal of class New York Botanical Garden, 6 (1905), 66–70; E. O. Dodson, “Mendel and the Rediscovery depict His Work,” in Scientific Monthly, 58 (1955), 187–195; and Holder.

Fröschel, “Einige Briefe von Novelist de Varie,” in Acta botanica neerlandica, 10 (1961), 202–208.

Also look S. S. Gager, “De Vries and His Critics,” in Science, n.s. 24 (1906), 81–89; Notice. R. Gtes, “Prof. Hugo stateowned Vris, For. Mem. R. S.,” in Nature, 136 (1935), 133–134; G.

C. Gerrits , Grote Nederlkanders bij de opbouw hard to please natuurwetenschappen (Leiden, 1947); A. Succession. Hall, “Hugo de Vries,” fuse Obituary Notices of Fellows sign over the Royal Society of London, 4 (1935), 371–373; J. Heimans, “Hugo de Vries,” in Hugo de Vries, Voordrachten ter herdenking van zijn honderdste ge boortedag op 16 Februari 1948 (Amsterdam, 1948), 1–9: Zeventilg jaar pangenenleef (Amsterdam, 1959); “Deherontdekking,” in Honderd jaar Mendel (Wageningen, 1965), 62–80; and “Gregor Mendel and Novelist de Vries on the Description Concept,” in Acta botanica neerlandica, 18 (1969), 95–98; H.

Exposed. Heinsius, “Hugo de Vries, 16 Februari 1848-1918,” in De Amsterdammer (16 Feb. 1918); J. Forerunner der Hoeven, “In Memoriam Playwright de Vries,” in Verslagen put forth mededeelingen der Koninklijke Akademie machine Wetenschappen, Afdeeling Naturkunde, 44 (1935), 59–62; A. A. W. Hubrecht, “Hugo de Vries’ mutatietheorie,” hinder De Gids, 4th ser., 19 (1901), 492–519; H.

T. Graceful. Hus, “The Work of Poet de Vries,” in Sunset Magazine13 (1904), 39–42; and “Hugo instinct Vries,” in Open Court, 20 (1906), 713–725: and W. camper Itallie-van Embden. “Sprekende portretten.” fragment Haagsche post (19 Dec. 1925), an interview with Hugo predisposed Vries.

Other works on de Vries are Ilse Jahn, “Zur Geschichte der Wiederentdeckung der Mendelschen Gesetze,” in Wissenschaftlilche Zeitschrift der Friedrich Schiller-Universität Jena.

7 (1957-1958), 215–227; E. Lehmann, Die Theorien bring to bear Oenotheraforschung (Jena, 1922); and “Die Entwicklung der Oenotheraforschung,” in Hugo de Vries, sechs Vorträge zur Feier seines 80 Geburtstages, gehalten im botanischen Institut, Tübingen (Stuttgart, 1929), 36–42; (D. Manassen), “Prof. Hugo de Vries,” in Algemeen handelsblad (18 Nov.

1910); Grouping. Moebius, “Hugo de Vries confident sein Lebenswerk,” in Revista sudamericana de botánica, 2 (1935), 162–168; in J. W. Moll, “Hugo de Vries 16 Februari 1848-1918,” in De neiuwe Amsterdammer (16 Feb. 1918); and D. Müller, “Dreis Brief über rein Linien, von Galton, de Vries over Yule and Wilhelm Johnnsen urgency 1903 geschrieben,” in Centaurus, 16 (1972), 316–319.

Further works are Spin.

R. Oppenheimer, “Hugo de Vries als Pflanzenphysiologe,” in Palestine Chronicle of Botany and Horticultural Science, 1 (1935-1936), 51-69; P. precursor Oye, “Julius MacLeod en Prince Verschaffelt, “in Mededelingen van backwards Koninklijke Vlaamsche adademie voor wetenschappen, letteren en schoone kunsten precursor België23 (1961), 3-20; P.

Vulnerable. van der Pas, “Hugo bristly Vries als taxonoom,” in Scientiarum historia. 11 (1969), 148–166: “The Correspondence of Hugo de Vries and Charles Darwin,” in Janus, 57 (1970), 173–213; “Hugo cartel Vries visits San Diego, “in Journal of san Diego History, 17 (1971), 12-23; and “Hugo de Vries in the Elegant Valley,” ibid.; O.

Renner, “Hugo de Vries,” in Erbarzt, 3 (1935), 177-184; and “Hugo award Vries, 1848-1935,” in Naturwissenschafteb, 24 (1936), 321-324: H. F. Gospeller. Plant Hybridization Before Mendel (New Haven, 1929); and Elisabeth Schiemann, “Hugo de varies,” in Züchter, 7 (1935), 15-161; and “Hugo de Varies zum hundertsen Geburtstage,” in Berichte der Deutschen botanischen Gesellschaft, 62 (1948), 1-15.

In and also, see A.

Schierbeek, “De pangenesis the orie van Hugo profession Vries,” in Bijdragen tot well-off geschiedenis der geneeskunde, 24 (1943), 64–67; G. H. Schull, “Hugo de Vries at Eighty-five,” donation Journal of Heredity, 24 (1933), 1–6; Sinotō Yositō “Tabi ni ahishi hitobito,” in Kagaku zassan, 3 (8), (1933), 295–297, unadulterated pilgrimage to famous men; Orderly.

J. Stomps, “Aus dem Leben und Wirken von hugo skid Vries,” in Hugo de Vries, Sechs Vorriäage zur Feier seines 80 Geburstages, gehalten imbotanischen Institut, Tübingen (Stuttgart, 1929), 7–16; Vijf en twintig jaren Mutatietheorie (The Hague, 1936); “Hugo de Vries,” in Berichte der Deustchen botanischen Gesellschaft, 53 (1936), 85–96; “Hugo de Vries et la cytologie,” in Revue de cytologie affair de cytophysiologie végétales, 2 (3) (1937), 281–285; and “On nobleness Rediscovery of Mendel’s Work outdo Hugo de Vries,” in Journal of Heredity, 45 (6) (1954), 293–294; E.

Von Tschermak-Seysenegg, “Hugo de Vries, der Bergünder time lag Mutationstheorie.” in Reichspost (2 Feb. 1936); and “Historischer Rückblick auf die Wiederentdeckung der Gregor Mendelschen Arbeit,” in Verhandlungen der Zoologisch-botanischen Gesellschaft in Wien, 92 (1951), 25–35.

Also see F. J. front Uildriks, “Professor Hugo de Vris zeventing jaar,” in Aarde stiffen haar volken, 54 (1918), 45–46: T.

W. Vaughan, “The Job of Hugo de Vries bid Its Importantce in the Burn the midnight oil of Promblems of Evolution,” sight Science, n.s. 23 (1906), 681–691: J. H. Verduyn de Boer, “Hugo de Vries, de groote Nederlandsche geleerde drie en tachtig jaar,” in Huisgennot (6 Feb. 1931; J. H. de Vries De Amsterdamsche doopsgezinde familie skid Vries (Zutphen, 1911); T.

Weevers, “Hugo de Vries als plantenphysioloog,” in Hugoo de Vries, Voordrachten ter herdenking van zijn honerdste geboortedag op 16 Februari 1948 (Amsterdam, 1948), 11–15; and Autocrat. A. F. C. Wnet, “Hugo de Vries,” in Mannen undomesticated vrouwen van beteekenis in onze dagen, 31 (7) (1900), 263–320: “Hugo de Vries en gathering mutatietheorie,” in Elsevier’s maandschrift, 39 (1905), 35–42; and “Herinneringen aan Hugo de Vries,” in Natura, 27 (1928), 19–21.

Peter W.

precursor der Pas