In the month of June 1906, San Diego was visited by one of the greatest scientists of that time. His arrival was announced in the list of guests of the Coronado Hotel for 4 June 1906, where he was listed as Col. Hugo de Vries, Amsterdam. The “Col.” cannot be a southern title, for Hugo de Vries never visite Kentucky, nor was he ever in military service. Except for this announcement, his visit went unnoticed. Nobody apparently greeted him at the railway station, nobody acted as his Cicerone. Alone, he wandered over San Diego’s hills and the mesa, enjoying the plants which grew there and admiring the view.
Hugo de Vries was a Dutch botanist who was then at the height of his fame as the originator of the mutation theory and one of the founders of the science of genetics. He was very impressed with the desert around the city, comparing it favorably with the deserts of Arizona, which he had visited two years earlier and which he had revisited only a few weeks before. He wrote an enthusiastic chapter about this visit in the book which described his peregrinations. But, like his visit, this chapter was never noticed in the United States, the book having been written in the Dutch language. Here, for the first time, a description is offered of early San Diego, as seen through the eyes of one of the leading botanists of the world.
Hugo de Vries was born in Haarlem, in The Netherlands, on 16 February 1848, the oldest son of an old and influential family. Already as a boy, he was very much interested in plants and flowers, witness the fact that already as a gymasium (secondary school) student, he was invited to help with the arranging and labelling of the plants in the herbarium of the Netherlands Botanical Society. Hence, it was to be expected that he took up the study of botany at the University of Leiden, where his father and many of his relatives had also studied.
At the University, the emphasis of botanical studies was on plant systematics, a field with which Hugo de Vries already was well acquainted when he started his studies there. As a result of private studies, he became interested in two other aspects of botany, plant physiology, then an upcoming science, and the theory of evolution, which was becoming prominent after the publication of Darwin’s Origin of Species in 1859. But in neither of these fields did he find support from his professors and it was with some trouble that he obtained approval for the subject of his doctoral dissertation, a topic in plant physiology.
De Vries was awarded his degree in October 1870. Being dissatisfied with his education in Leiden, he decided to continue his studies abroad. He worked for one half year in the laboratory of the famous plant physiologist Wilhelm Hofmeister in Heidelberg and thereafter moved to Würzburg, where he intended to work for several years in the laboratory of the even more famous plant physiologist, Julius Sachs. However, in the fall of 1871, the position of natural history teacher at the first high school of Amsterdam was offered to him and, probably at the insistence of his parents, he accepted. For the next fours years, he taught in Amsterdam during the school year, but as soon as summer vacations started he was on his way to Würzburg to work in the laboratory of Sachs.
De Vries had accepted the job in Amsterdam only reluctantly, and as time went by he disliked his job more and more. Therefore he jumped at the opportunity, opened after Sachs proposed to the Prussian Department of Agriculture in 1875, to charge de Vries with the writing of monographs on cultural plants for its yearbook. De Vries came to Würzburg to work on these monographs. He wrote three of them. Two years later Sachs obtained for him the position of lecturer in plant physiology at the University of Halle. This job was far from a success. He had only three students of which two turned up for the lectures only occasionally. Therefore, de Vries was quite happy when, in the fall of 1877, he was appointed lecturer of plant physiology at the University of Amsterdam. Here he became a full professor in a few years.
In Würzburg, de Vries has worked exclusively in the field of plant physiology, initially under the close guidance of Sachs, later more independently. In Amsterdam, he continued this line of research, and because of his spectacular results he soon was recognized as one of the leading botanists of Europe. Now being completely free to follow his own inclinations, he devoted more and more time to his old interest, the theory of evolution. Being of a systematic mind, he explored all avenues which might lead to a better understanding of the mechanism of evolution, and finally he decided that the study of heredity offered the best chance to gain a deeper insight therein. Since about 1890 he devoted all his time to studies of heredity.
During the years between 1890 and 1900 he made two great discoveries. One of these had been made before, but had attracted no attention. This discovery concerned the laws of Gregor Johann Mendel which explained the normal phenomena of heredity. The second one was mutation, the fact that sometimes the offspring of plants looked so much different from the parents that one had the impression that an entirely new species had arisen.
De Vries discovered his first mutations in the evening primrose, the Oenothera, and later in other plants. The laws of Mendel allowed the prediction of the result of crossing two plants, even after many generations. Therefore, de Vries considered these laws of no great importance for the ‘explanation of evolution in which he was actually interested. He discovered Mendel’s laws in about 1896, but he waited four years to publish his results. When he did publish them, the reaction of the scientific world was quite unexpected; an enormous interest was shown everywhere. Many investigators started to work in this field, and the science of genetics was born.
De Vries, however, considered his discovery of mutation the most important of the two; he left the further investigation of Mendel’s laws mainly to others, but he worked with mutating primroses for the rest of his life.
After 40 years as a professor in Amsterdam, de Vries retired. He went to live in Lunteren, a small village, where he had built a laboratory and had started his experimental garden. Here he continued his work until his death on 21 May 1935.
Until 1900, the year in which the rediscovery of Mendel’s laws was announced, although de Vries was very well known in Europe, he was relatively unknown in the United States. The explanation for this is probably that in the United States there was, at that time, relatively little interest in plant physiology; the main interest of the botanists being plant systematics and practical aspects of botany such as plant breeding. The publication of 1900 changed this completely. American botanists started to contact him, visit him and invite him to their congresses. However, it was not easy for de Vries to accept such invitations. During the fall and the winter semester, he had to give his lectures, while the spring and summer were devoted to his cultures of mutating plants.
In 1904 de Vries received an offer from the University of California in Berkeley to teach a course on mutation and heredity at the summer school. This offer he could not turn down. He spent a considerable time in preparation for his journey, quizzing his colleagues at the university on the geography and geology of the United States and opening up a correspondence with American colleagues through the services of the administration in Berkeley. His trip was a great success. Everywhere he was received most cordially. He received more invitations to lecture than he could possibly present; and was awarded several honorary degrees. When he returned home he had sufficient material on what he had seen and experienced to fill a book, which was published in the Dutch language under the title, “Naar Californie.” This book was a great success in Holland. Two years later it had to be reprinted, this time under the title, “Naar Californie I,” because in 1906 de Vries had been asked to attend the Franklin Centenary celebrations in Philadelphia and about this second trip he wrote another book entitled “Naar Californie II.” On this second trip he again presented a series of summer lectures in Berkeley.
De Vries visited the United States for a third time in 1912 on the occasion of the opening of Rice Institute in Houston. On this trip he did not visit California again, but instead he explored Texas, Florida, and Alabama, and again he wrote a book about his trip, “Van Texas naar Florida.”
These three U.S. travel books are still well worth reading, especially the ones on California. They, describe the state in its pioneering time when many great men were busily engaged in converting a wilderness into a civilized country. They are especially of botanical and agricultural interest, having been written by an excellent botanist and a keen observer. Unfortunately they have never been translated into English.
It was on his second trip, in 1906, that de Vries visited San Diego. This visit was actually purely incidental. He had planned to attend the Franklin celebrations, 17-20 April, thereafter to return to New York for a week or so, and subsequently to travel west, staying one day in Manhattan, Kansas, about a week in the Grand Canyon, a few days at the petrified forest near Holbrook, Arizona, and several weeks in Los Angeles, aiming at arriving in Berkeley at the beginning of the last week in June. In Manhattan he stayed with H. F. Roberts, at that time a young professor of plant breeding at Kansas State College of Agriculture and Applied Sciences. De Vries and Roberts must have gotten along very well for instead of staying for a day, as originally intended, he stayed for almost two weeks, 3-17 May. Consequently he had to shorten his visit to the Grand Canyon and the petrified forest from the two weeks which were originally planned to three days. He finally arrived in Los Angeles on 24 May 1906. It was his intention to explore Southern California using Los Angeles as a center, and it is from there that he visited San Diego. A visit to San Diego had not been in the itinerary at all, but Roberts had persuaded de Vries to visit the city by all means.
De Vries knew nobody in San Diego and it is doubtful that Roberts knew anybody there well enough to give him a letter of introduction. The exact duration of his visit is unknown; he sent a postcard showing the children’s playground at the International Lotus Home, Point Loma, to his family on the fifth of June 1906, a Tuesday.
Hugo de Vries described his impressions of San Diego as follows:
San Diego is probably known best to my readers as the center of Theosophy. The city is located in the most southern part of California at the coast of the Pacific Ocean, at a bay which, except for the bay of San Francisco, is the only natural harbor of the state. The bay is surrounded by two peninsulas. The most southern of these is a long, narrow dam with a double “head,” the most north of which1 is flat and has no buildings while the other head2, separated from the former one by a narrow channel, is entirely covered with villas and houses and is very well known for the large hotel, the Hotel del Coronado. Its climate and beaches are very desirable. The northern peninsula is a narrow chain of hills, between 400 and 500 feet in height and is mainly used for military purposes. It is called Point Loma. A light house, a station for wireless telegraphy, and a large fortress are its main points of interest. Close to the northern boundary of this military reservation, the grounds of the International Theosophical Center, of which the building of the Raja Yoga Academy, built in a nordic style on top of a hill and provided with a large glass cupola, attracts the eye from all directions. The grounds measure 1200 acres and it is planned to build a great, central university there at a later time. Therefore the buildings are only preliminary and constructed of wood, covered with cement which is reinforced with wire matting. The grey color looks very satisfactory in the grey desert.
The entire Foundation is under the direction of Catharine Tingley, who started it some twelve years ago. Next to the building of the Academy other buildings were soon erected, the Aryan Temple for music and some smaller buildings and bungalows. The Foundation has the purpose of propagating the principles of Theosophy and in addition, the education of children, orphans and abandoned children as well as the children of more well to do people. One would not guess this from the name “Academy,” but this is a name in American style3. The most important buildings are the Raja Yoga school and the Children’s International Lotus Home, while there are some more schools in San Diego and elsewhere. The Raja Yoga system of education is aimed at practical purposes and at equal development of body and mind.
Close to the Academy there is a curious hotel. It is called Tent-Village4 and does not actually have a building. The rooms are tents consisting of a square wooden frame with a door and windows, but the roof and the walls are made of linen. The floor is made of wood, the couches are converted into beds in the evening and only the most necessary furniture is provided. Each tent houses one to four persons. If a tent is not in use, it is simply put into storage. There is an office tent, a tent which serves as a dining room, and another one which serves as a waiting room. This hotel, which had about 25 tents when I visited, has a Tallyho, a tent wagon, to reach the shore of the bay and from there a little steam ship brings you across the bay into the city. There is a nice ride, about three quarters of an hour, from this hotel to the light house, either to the old one on the farthest hill or to the new one at the beach. Here one can see the structure of the hills and their vegetation. The beach drops with a .vertical, stories high, wall towards the ocean. There are only a few places where there is an actual beach and where one can reach the ocean. This wall is made of clay-like rock, a rock which has been decayed into a hard clay which is continually eroded by the waves at its base. The undermined mass starts crumbling and caves in from time to time. This is accompanied with the formation of caves and arches, of protruding pillars which are at their top still connected with the remainder of the rock and have all kinds of shapes due to the difference in hardness of the various layers and the eroding action of the ocean water. Close to the light house one can approach these grottos and portals sufficiently close to see them well, but one cannot descend into them. Here also the ocean penetrates all of them. Enormous sea weeds of all kinds are seen here on the beach and one sees them floating in the water when crossing the bay. Twice man-size is an average length for many kinds of them.
San Diego has been built for the future, like so many other American cities. It is the second harbor of California and is directly connected by rail to the national railroad network. Hence there is a good possibility for the development of commerce.
The city has already been laid out in a system of streets which cross at right angles. Those which run in north-south direction are called A, B, C, D street and so on, while those which run in east-west direction are called first, second, third street and so on. But this system is not consequently followed, there is a group of streets; called Acacia, Beech, Cedar, Dracaena, Elm, Fir street5 and so on, names of trees in alphabetical order. This network of streets reaches far over the otherwise empty plain for miles outside the center of the city. Here or there a house, here or there a corn field, a lemon orchard or a produce garden, this is all one sees of the “city.” But the streets are there. With cement sidewalks and rows of young palm trees they traverse the bare desert. At places, where there are some houses already, one sees telephone wires, power lines, and cables for the electric streetcars.
The city is located against the slope of the hills. These hills are called mesa here and the mesa continues until the high hills, behind which one sees the mountains of San Jacinto and San Bernardino. From the Raja Yoga Academy one has a beautiful view, a long range of mountains, stretching from” north of Los Angeles until far into Mexico. But snow caps are not to be seen. The mesa separates the mountains from the coast. It consists of low hills which run in the direction of the ocean with numerous branched canyons and valleys through which the mountain streams transport the erosion products on the mountains and hills toward the bay. When I visited in the beginning of June, all these streams were dry and one could walk in their beds, although this was difficult on account of the numerous round boulders.
As far as one can see, the mesa and the mountain slopes are bare. Nowhere does one see a tree growing. Only along the beds of the mountain streams are high bushes seen; everywhere only chaparral or dry grass. Chaparral consists mainly of shrubs, about four feet high, of several kinds. In the beginning of June all this luxuriates in the brilliant hue of the spring flowers in the desert. Everywhere there are flowering shrubs, the tops and slopes of the hills show white patches among the dark green or light greyish blue or other colors. Between the dry grass millions of flowers are blooming close together, covering the slopes with yellow, red, white or violet patches.
On top of the hills grows a little shrub which covers the tops and highest parts of the slopes. It looks like a high heath shrub6 and has dark green, needle-like leaves. It flowers everywhere with white bunches of small flowers which contain much honey. At some spots on the slopes one sees bee hives, and indeed, thousands of bees are humming above the flowers. It is the Adenostoma fasciculatum (chamise), which is related to our meidoorn7, but has smaller flowers and different leaves. The numerous flower bunches are contrasted strongly against the dark green foliage, and even at great distances one can recognize the stands of this plant on the hills of the mesa.
Between these heather-like shrubs one sees at some spots other shrubs with small leathery leaves. For example an oak-like8 shrub, a Ceanothus with flat, red, sticky berries, Ceanothus verrucosus and an Erigonum (wild buckwheat) which has heath-like leaves also, but much more dense in its needle-like leaves and with bunches of white or pink flowers. This is Erigonum asciculatum. At some spots this plant crows out the Adenostomas completely. Sometimes, entire mountain slopes are colored a light grey, being covered with the black sage, Salvia mellifera, a grey shrub which carries, on long stems high above its leaves, an almost spherical bunch of light-greyish-blueish flowers. Everywhere one sees humming birds flying around, and in one of these sage shrubs, I actually found the nest of a humming bird or some other, related bird. Another kind of sage, the Salvia californica, is grey also, but has much longer and thinner flower bunches of the same color. These are the most strange flowers one can see. The upper lip is small, but the lower lip very large and folded over the tube of the flower and the other lip in such a way that the entrance to the flower is closed and the two long stamens and the pistil are pushed away to the left and the right. If one approaches the streams, the shrubs become higher and other species are seen, species with more leaves.
At the beach the same forms are found, and also a kind of sagebrush related to that useless kind of plant of the same name, which covers enormous areas in the deserts of Arizona and the Yellowstone Park and other areas of the semi-arid plains region. This plant is the Artemisia californica, called worm-wood on account of its use in medicine, but also “old man,” on account of its branches with gray leaves which do not grow vertically, but horizontally on account of the wind. All the shrubs near the ocean beach are lower, as if they were kept low by the wind, and many of them were already drying out in June.
Between those shrubs one sees Yucca’s and Cacti everywhere. The Raja Yoga Academy has a small botanical garden where about ten of the most common shrubs are labelled with their Latin and English names. Here I discovered the name of the large disk-like cactus, Opuntia Engelmannii, which is so conspicuous in the desert with its strange shape and large yellow or red flowers with innumerable stamens. Sometimes I saw this plant crawling low over the ground, but between the shrubs it grows high, and it often elevates its large discs above them. Near the ocean beach I saw some wide, ascending valleys covered nearly completely with this cactus, a strange, but not displeasing sight. The disks carry numerous thorns, grouped together near the soft, juicy, reddish-brown, thorn-like leaves, which dry out later, a reminder of the fact that thorns originate from leaves. Another cactus with cylindrical trunks and branches, Cereus, has still stranger shapes, spookly shapes even sometimes, on account of branches which grow downward giving the impression that the plant stands on two legs, sometimes with arms and a head also, and even stranger shapes. A much rarer spherical cactus with large, hard thorns, is the Echinocactus viridescens; I found only a few of those.
I did not see Yucca’s in bloom here. Only their bundles of narrow leaves with sharp treacherous points were seen here and there between the green foliage. On acocunt of these points they are called “spanish daggers” here. This is Yucca mohavensis. Elsewhere, in the San :Bernardino mountains, I saw the Yucca in bloom, man-high bunches of bright, bellshaped flowers as far as one could see, growing between the Adenostomas and other shrubs, towering high above them. At other places I saw the tree-like variety which look like fossil trees9 or the dragon tree10 with few, but thick branches, each of which carry a rosette of dagger-like leaves.
Among the shrubs I still should mention the Yerba Santa and the tree tobacco. Yerba Santa or Eriodyction tomentosum has large, soft, grey-haired very fragrant leaves with beautiful violet-blue bunches. The tree tobacco or Nicotinum glauca is a high- shrub which grows mainly along the streams and has green bunches of tobacco flowers. It is one of the wild species which Luther Burbank tries to cross with cultivated species to obtain perennials from the beautiful fragrant annual species. 11
More numerous than the shrubs and with more beautiful colors are the flowers found among the dried grass. They all are annual spring flowers, now in full bloom, but soon to be dried out and withered. On the sea side of the hills near Point Loma most of the annuals were already dried out and full of seed. The flowering season had passed here. But east of San Diego, and especially in the Las Choyas valley, I saw them in full bloom everywhere. A most beautiful view which can compete with our most beautiful flowering meadows and dune valleys. The type of flower is partly also similar to the flowers found in our dune valleys. But here we find only plants which require little water. They depend only on the -rain for their germination and they germinate in large numbers during the few rainy days in spring. As the rain water descends slowly in the soil, the roots grow accordingly and manage to absorb sufficient water for their flowering and the setting of seed. Therefore, most kinds set seed very quickly and produce very much of it; plants which cannot do this, cannot survive in the desert. This also explains why they grow in large groups together. Millions of them grow close together at one spot, but a little farther on none are to be seen. This probably is due to accidental circumstances and the rain, which causes some species to multiply fast and causes them to die out perhaps even faster.
This is shown most beautifully by centaurea (canchalagua), Erythraea venusta.12 It has much bigger flowers than ours, bright red stars, which are larger than a dime, with white hearts. Sometimes one plant carries 50-60 flowers. I saw large fields of them, thousands flowering on the hill slopes. But always either very many together or none at all, never just a few isolated plants. At some spots a white variety grows, and I saw also from time to time a pink variety. Other fields sported delicate white flowers, very like small bluebottles (corn flower) 13 on richly branched plants. Other fields had the red little flowers of Chorizanthe which grows very low, but yet covers large fields. Other fields were white with Phacelia of which the flowers look like forget-me-nots, but yellow is the most common color. Yellow tar weed Hemizonia, yellow flowering plants looking more like immortelles grew everywhere and between them yellow Oenotheras114. The latter are creepers with flowers and leaves which look like wall flowers15; their name is Oenothera cheiranthifolia. But the flowers are more yellow and larger and the petals are wider than in the wall flowers. These flowers had four dark brown spots in the center.
Between these more common plants there were also some which occurred less frequently and in smaller numbers. Red thistles and white bind weed (Convolvulus), shrubs of a yellow Lotus with long flower bunches which turn brownish-red when they wither (Lotus glaber), many white straw flowers of all kinds (Antennaria), a few violet desert tulips (Calochortus), the small blue-eyed grass Sisyrrhynchum bellum, the reddish violet Mirabilis californicus, yellow Mimulus (monkey flower) and especially the bright red delicate stars of the campion (Silene ciliata). The monkey flowers (Diplacus)16, which are light orange-yellow near Berkeley range from dark orange to brown here. I saw many other species, too many to mention here and many were unknown to me, but they were all beautiful and vividly colored, an inexhaustible source of pleasure, even for those who do not know much of botany.
The few cultured plants which I saw show how mild the climate is here. Most numerous of these are the palm trees. Fan palms (Washingtonia filifera) are the most common trees along the streets, but I saw cocos palms also on a square in San Diego, and the date palm of the Canary Islands grows here in beautiful specimens, often laden with yellow plumes, full of edible dates. Two Ptychospermas17 which in our country flower only in the hot houses, flowered here outside in the garden of the hotel. Lemon trees laden with fruit, olive trees almost in flower, century plants with their high flower stems, Grevillias covered with yellow flowers were seen all around, and also tree-malva’s and tree-hibiscus with their large flowers, richly flowering pomegranates18 and, of course, everywhere the dark green, thickly branched Monterey-cypress and Eucalyptus trees, of which the most common kind, Eucalyptus Globulus, was covered with large white flowers. Eucalyptus means “with a hat,” and indeed, the flowers sheds its green hat, the calyx, when it unfolds. Yellow Acacias (Acacia melanoxylon) are, as in Los Angeles and farther north, common street trees here also; in our country they grow in hot houses only. The sweet verbena (Lippia citriodora), sometimes called lemon-verbena, grows here with trunks as thick as your arm.
In the borders around the garden or along the sidewalks one sees mostly Geranium here, or also a small kind of ice plant (Mesembryanthemum). Both have pale violet flowers, and borders of several feet wide and several hundred feet long are not rare. One seems them ascending the slopes of the hills between the palm trees. A curious lawn plant, the Lippia nodiflora (mat-grass), is mowed short just like a lawn of grass or clover, and covers the entire lawn with light violet flowers in spring. Other ice plants, especially the common Mesembryanthemum crystallinum, often grown in our country for its ice colored bubbles, is seen very much here in the desert; especially near the ocean one sees large fields covered with the delicate ray flowers. Sometimes one has to walk over them, but the breaking “ice bubbles” make the plant slippery; it is difficult to walk on them. Of course, they do not contain ice, but water. I saw them at some places as a weed between the wheat and rye fields, because developing the desert here has begun only a short time ago.
Weeds follow mankind into the desert. I saw common salt bush19, chamomille20, wire grass (Polygonum aviculare), sunflowers which were already in bloom, fennel21 which was a common weed in Los Angeles also, the Napathistle22 which sometimes forms a yellow border along the roads for miles and very often yellow mustard (Brassica nigra) and many other imported species.
A curious plant is the rattlesnake imitator. 23 It belongs to the pea family and has bunches of six to twelve dry pods, in which the seeds lie loose and make a rattling sound if the wind moves them. It resembles the sound of the rattlesnake and this sound has frightened many, for rattlesnakes are found here, although not more than adders in our country. But their bite is far more dangerous. From a distance the pods look like yellow berries; they adorn the hills with their millions of bunches.
Still stranger are the orange-yellow bundles of a kind of “devils-yarn,? 24 which vegetates on all kinds of low shrubs and looks like large groups of flowers from a distance. But they consist of thin threads which run in all directions and they hardly ever flower. Strange also is the fact that one finds ferns in the desert. But these are kinds which can dry out and come to life again when wetted; they are dry curled leaves covered with a white powder on the back. I did not see many of them however.
The Echeverias are curious plants also. They are known as “fat-plants” in our country; they grace our gardens sometimes with their beautiful rosettes. Here, a white, narrow leaved kind and a red scaly kind are found. Their flowers resemble our Cotyledon californicus.
Everywhere from the mesa one could see the city, the bay with its two peninsulas, Point Loma and the Raja Yoga Academy, and behind all this, the beautiful dark blue water of the Pacific, always calm, as indicated by the name, only breaking its waves with a thundering sound where the shore is steep. The desert of Arizona is monotonous, abandoned and desolate, but here the desert is full of life and flowers, full of variety and beautiful vistas. A very fertile, hard clay and a moist air enable the plants to grow vigorously and give promise that the entire area can be developed agriculturally. The Raja Yoga Academy is leading in this respect. Very near the beach mulberries for silk culture are cultivated, also lemons, peaches, apricots, wheat and rye, insofar as I can see and hear from others, with great success. At some places hedges of Monterey cyprus are necessary to protect the crops, but for many of them this is not necessary. Planting trees sometimes requires temporary irrigation, but after the roots are developed well they can take care of themselves. Here the wheat was much higher and fuller than the wheat I have seen in irrigated fields of lower lying deserts. In spite of this, it seldoms rains here, but the sea air is sufficiently moist and the sky often is cloudy, which retards evaporation and prevents drying out.
This area may perhaps have as great a future on land as it has on the sea, while attempting to be a center for ideas of unity and brotherly love.
Apparently Hugo de Vries did not visit Old Town. He mainly wandered along the streets of the as yet unbuilt city and Point Loma. His choice of where to go is understandable; he was greatly interested in the flora of the desert, in the “struggle for life” of the plants under the adverse conditions under which they were living and in the manner they adapted themselves to live and propagate in surroundings with scarce water, a year-around sunshine and a continuous wind. These conditions were quite different from those of his home country, where water never was a problem, where every sunny day is cherished, and where, therefore, the plants act quite differently to maintain themselves.
De Vries returned to Los Angeles and made more excursions from there to the San Bernardino mountains, to the island of Catalina and several more. From there he went to Berkeley where he lectured for about a month and traveled back to New York via Chicago and from New York back home. In later letters he often expressed his desire to return once more to California, but this was not to happen. He never returned.
1. North island.
2. Coronado island.
3. In Holland an Academy is either a university or a learned society.
4. This is what Hugo de Vries called it.
5. Were the names of some of these streets changed since 1906, or did Hugo de Vries fail to consult a map when he wrote this chapter of his book?
6. Hugo de Vries wrote for Dutch readers and therefore he compares American plants with Dutch ones. The heath shrub Calluna vulgaris, about one foot high with many, usually violet flowers, covers large areas of the sandy grounds in Holland.
7. The meidoorn is Crataegus (hawthorn) of which several species grow wild in Holland.
8. The leaves of some Ceanothus species indeed look like those of the oak trees of Holland, however, Ceanothus does not belong to the oak family.
9. This is Yucca brevifolia, the Joshua tree.
10. This is Dracaena Draco. It indeed looks like a Joshua tree, but is much taller. Yucca and Dracaena are both genera of the lily family.
11. Hugo de Vries visited horticulturist Luther Burbank several times, both in 1904 and (after his visit to San Diego) in 1906. He was the foremost champion of Burbank in Europe. Burbank succeeded in crossing various tobacco species, but the hybrids were all sterile and the plant was never marketed.
12. Now called Centaurium venustum.
13. This is Centaurea cyanus, a flower which used to grow in the wheat fields, but is now not seen so much any more on account of the introduction of purified wheat seed.
14. The Oenothera was a plant genus especially dear to the heart of Hugo de Vries, for it was in this genus that he found his first mutations. He cultivated many species from about 1890 until his death in 1935.
15. This is Cheiranthus cheiri. The species name of the Oenothera which Hugo de Vries found in San Diego means: “with leaves like a wall flower.”
16. Hugo de Vries is mistaken here. The monkeyflower is Mimulus; Diplacus is however a genus closely related to the monkey-flower.
17. A palm species from New Guinea and neighboring Pacific islands.
18. Punica granatum.
22. Centaurea melhensis.
23. This is rattle-weed or loco-weed, Astragalus.
24. This is the translation of an old name of a parasitic plant. It is now called “warkruid” in the Dutch language. The English name is “dodder,” the Latin one: Cuscuta.
Peter W. van der Pas, who holds a degree in physics from the Institute of Technology, Delft, Holland, has contributed papers on subjects in the history of science to various journals such as Archives Internationales d’Histoire des Sciences, Janus, Scientarium Historia and to the International Congresses for the History of Science in Ithaca (1962) and Paris (1968). He is currently working on a biography of Hugo de Vries. All illustrations except the De Vries portrait are provided through the courtesy of Title Insurance and Trust Company, San Diego, California.