Campbell, Douglas Houghton

(b. Detroit, Michigan, 16 December 1859; d. Palo Alto, California, 24 February 1953),

botany.

Campbell was the fifth of the six children of James V. Campbell, one of the first three justices of the Michigan supreme court. The first three decades of his life were spent in Michigan, first at Detroit High School (until 1878), then at the University of Michigan, Ann Arbor (1878–1882), where he received his master’s degree. He then returned to Detroit High School to teach botany (1882–1886). He received his doctorate from Michigan in 1886 on the basis of studies carried out on the structure and fertilization of fern gametophytes. His working habits at this time set the pattern for the rest of his life. He taught in the mornings, researched in the afternoons and evenings, and by living at home accumulated enough money to support himself for two years of research in Germany (1886 to 1888). After working in Berlin, Bonn, and Tübingen, he returned to the United States and was appointed professor of botany at the University of Indiana (1888–1891). His second and final appointment was to the chair of botany (1891–1925) at the newly founded Stanford University. In the remaining twenty-seven years he lived in his own house on the campus as an emeritus professor.

Campbell’s first paper appeared in 1881 when he was in his early twenties, his last in 1947, when he was nearly ninety. He was an editor of the American Naturalist, a member of the American Academy of Sciences (from 1910), and president of both the Botanical Society of America (1913) and the Pacific section of the American Association for the Advancement of Science in 1930. Campbell never married.

Botany in the 1880’s was dominated by the German school of cytologists led by E. A. Strasburger. The cell theory of M. J. Schleiden and T. Schwann had been corrected and the role of the nucleus and the structure of the nuclear threads (chromosomes) were being explored, chiefly by W. Flemming. The relevance of the cell theory to plant embryology and phylogeny had been brilliantly explored by W. Hofmeister. By detailed and far-ranging studies of the life histories of the lower plants he was able to dispose of the erroneous analogies which had been made by men like Schleiden between the spores of fungi, algae, liverworts, mosses, and ferns and the pollen grains of flowering plants. Instead Hofmeister identified the true analogies between lower and higher plants (cryptogams and phanerogams) with the sexual organs of the gametophyte generation. Campbell read Hofmeister’s The Higher Cryptogamia (1862) in his student days at Michigan. It fired him with enthusiasm for the study of the Cryptogamia.

Filling in the details of Hofmeister’s scheme and constructing a phylogenetic tree for the plant kingdom occupied the attention of a growing number of botanists and cytologists during the latter part of the nineteenth century and the first two decades of the twentieth. To this program of research Campbell contributed both during his two years in Germany and afterward. Along with F. O. Bower, the British expert on plant phylogeny, Campbell contributed to the theoretical discussions on the subject of the origins of a land flora. His book The Structure and Development of the Mosses and Ferns (1895) was a landmark in the history of the subject and supplied the first systematic review since Hofmeister’s classic.

Campbell’s textbook was used in virtually all university botany departments so that before the turn of the century its author was universally known. His reputation was further enhanced by his Lectures on the Evolution of Plants (1899). These textbooks combined original findings with summaries of published work in a form suitable for the student. The exposition is clear and is all directed to one purpose—the clarification of the phylogenetic relationships of the lower plants. Campbell’s true love of natural history gave to these books a welcome touch, and his deep knowledge of ecological factors enabled him to see evolutionary significance in many obscure structures.

As a schoolboy, Campbell had been greatly impressed by A. R. Wallace’s Malay Archipelago (1869), and during his frequent journeys to the tropics, especially to Hawaii and to the mountain laboratory of the botanical garden at Buitenzorg, Java, he gathered valuable data on the growth and structure of tropical members of the Cryptogamia, especially of the Anthocerotaceae. From his time in Strasburger’s laboratory he was made aware of the exciting discovery of the details of cell division, and in Pfeffer’s laboratory he developed the use of vital stains. In later publications he drew the attention of American botanists to the ease with which the details of cell division can be demonstrated, but he failed at this time to apply his knowledge of chromosome mechanics to the explanation of alternation of generation. His style of writing was inferior to that of his friend Bower, which may partly explain why to all but a few Campbell is a forgotten name, a man who lingered on while the fashion of the science he knew and loved changed almost beyond recognition. In part this is because he did not broaden his work in the direction of palaeo-botany to anything like the extent that Bower did. Whereas Bower wrote for the advanced student, Campbell wrote for the beginning student. Some of his popular writings—An Outline of Plant Geography, for instance—were judged very superficial.

Campbell’s original papers, however, were anything but superficial. In a highly competitive field, to which a great number of botanists contributed, Campbell supplied numerous details gained from very careful study of material. While working in German laboratories, Campbell was introduced to the techniques of microtome sectioning of tissue embedded in paraffin wax. He quickly wrote up an account of this technique as applied to botanical material and published it in the Botanical Gazette for the benefit of American botanists. In his own hands it yielded him a most important find—the discovery of the precise manner of formation of the archegonia and antheridia in the eusporangiate ferns. On the factual side this led him to make many contributions to the knowledge of the details of gametophyte structure and habit from practical advice about the germination of spores to details of the division behavior of the apical cell. His view that the sporophyte of eusporangiate ferns is derived from an adventitious bud arising endogenously within the primary root is not now accepted, and his denial of the application of the stelar theory to the vascular organization of the Ophioglossaceae is questioned.

Campbell’s most important contribution was to link the ferns with the liverworts by way of Anthoceros. When his book The Structure and Development of Mosses and Ferns appeared, popular opinion, which included Bower’s, had it that the leptosporangiate ferns were the more primitive and were descended directly from the algae and that the mosses and liver-worts constitute a parallel evolution. Campbell was the first to suggest that the eusporangiate pteridophytes are the more primitive and have originated from the strange hepatic group Anthocerotales and to give as evidence the embedded condition of the antheridia and archegonia in Anthoceros and in eusporangiate ferns.

His analogy between the germ-cell portion of the eusporangiate antheridium and the whole of the anthocerotean antheridium, and between the eusporangiate jacket layer and the anthocerotean antheridial chamber is now the accepted view. Campbell went on to show that the sporophyte of Anthoceros can sustain itself for several months when separated from the gametophyte, that its chlorophyll-containing tissue is capable of photosynthesis to a limited extent, and that given a small supply of carbohydrates it can grow and sporulate (1917). In 1924 he described nine-month-old, sixteen-centimeter sporophytes of Anthoceros, showing differentiation and growing on withered gametophytes in the San Jose Canyon. These very important discoveries led Campbell to give increasing support over the years to the antithetic theory of the origin of the sporophyte generation. This theory, first outlined by L. Celavosky in 1874 and developed by Bower in 1890, regards the sporophyte of plants higher than mosses and liverworts as a new structure intercalated into the life cycle. In the course of evolution, it was suggested, the fusion nucleus formed from the antherozoid and oogonium, instead of rapidly producing a sporogonium filled with spores, as in mosses and liverworts, has progressively delayed the spore-forming process and has rendered more and more of the sporogonial tissue nonspore-forming.

According to the rival homologous theory, the sporophyte is a direct modification of the gametophyte, and there is no special significance in that the sporebearing generation always results from the product of sexual reproduction—the zygote. This view of the origin of the sporophyte was favored by J. M. Coulter but opposed by Campbell (1903). Today the antithetic theory is firmly established on the basis of the chromosome cycle.

Campbell’s advocacy of the antithetic theory went hand-in-hand with his belief in the anthocerotean origin of the eusporangiate pteridophytes. Little credence was given to the latter suggestion until R. Kidston and W. H. Lang discovered well-preserved fossil representatives of the psilophytons of the early Devonian in 1917. Before that time the gap between a rootless, leafless sporophyte of Anthoceros and the root- and leaf-bearing, free-living sporophyte of the pteridophytes seemed too large. In 1895 Campbell had referred to the strange fossil psilophyton which J. W. Dawson had discovered as early as 1859, the structure of which suggested a leafless and rootless sporophyte organization, but the incomplete nature of the specimen and the doubts thrown on it by H. Solms-Laubach, which Campbell appeared to accept, prevented the idea of a link between Anthoceros and the pteridophytes being established until better specimens became available (after 1917).

By the early 1920’s, it had become clear that plants lacking roots and leaves did exist as independent sporophytes in the early Devonian period. Campbell’s suggestion of the anthocerotean origin of the eusporangiate pteridophytes is now generally accepted, and it is for this idea and for his associated belief in the primitive character of the Eusporangiatae that he is remembered.

BIBLIOGRAPHY

I. Original Works. Campbell published more than 150 papers and reviews, seven books, one monograph, and a few pamphlets. Most of these are listed in Gilbert Smith’s biography (see below). Campbell’s books are Elements of Structural and Systematic Botany for High Schools and Elementary College Courses (Boston, 1890); The Structure and Development of Mosses and Ferns (Archegoniatae) (New York-London, 1895; 2nd, ed., 1905; 3rd, ed., 1918); Lectures on the Evolution of Plants (New York-London, 1899); A University Textbook of Botany (New York-London,1902); An Outline of Plant Geography (New York, 1926); and The Evolution of Land Plants (Embryophyta) (Stanford-London, 1940).

The development of Campbell’s views on the origin of the ferns can be traced in “On the Affinities of the Filicineae,” in Botanical Gazette, 15 (1890), 1–7; “Notes on the Archegonium of Ferns,” in Bulletin of the Torrey Botanical Club, 18 (1891), 16; “On the Relationships of the Archegoniata,” in Botanical Gazette, 16 (1891), 323–333; and “The Origin of the Sexual Organs of the Pteridophyta,” in Botanical Gazette, 20 (1895), 76–78. His work on the eusporangiate ferns is beautifully presented in “The Eusporangiatae. The Comparative Morphology of the Ophioglossaceae and Marattiaceae,” in Carnegie Institution of Washington Publications, no. 140 (1911). His important studies of Anthoceros can be found in “Studies on Some Javanese Anthocerotaceae, I,” in Annals of Botany, 21 (1907), 467–486; pt. II, ibid., 22 (1908), 91–102; “Growth of Isolated Sporophytes of Anthoceros,” in Proceedings of the National Academy of Sciences, 3 (1917), 494–496; and “A Remarkable Development of the Sporophyte in Anthoceros Fusiformis Ausr.,” in Annals of Botany, 38 (1924), 473–481.

II. Secondary Literature, Neither the general scientific periodicals nor the specialist botanical journals appear to have carried obituary notices of Campbell, but biographical information can be found in the essay by G. M. Smith, “Douglas Houghton Campbell,” in Biographical Memoirs, National Academy of Sciences, 29 (1956). 45–63, with portrait and bibliography.

For an authoritative discussion of Campbell’s contributions, see Gilbert M. Smith, Cryptogamic Botany, vol. II of Bryophytes and Pteridophytes (New York-London, 1938).

Robert Olby