Brefeld, Julius Oscar

(b. Telgte, Germany, 19 August 1839; d. Schlachtensee, near Berlin, Germany, 7 January 1925)

mycology.

Oscar Brefeld, a founder of modern mycology, developed pure culture techniques and a comparative morphological approach in the study and classification of fungi, pioneered in researches on the cereal smuts, and published, over a period of forty years, a monumental fifteen–part treatise on his observations.

He was born in a small town near Münster in Westphalia, the third of four children (two sons and two daughters) of Wilhelm Brefeld, a prosperous pharmacist, and his wife Franziska Povel. Since the elder son, Ludwig, had studied law (in due course he became Prussian minister of trade and commerce), the other son was expected to follow his father’s profession. Accordingly, having attended school in Telgte and completed his year of military service, Oscar studied pharmacy at Breslau for a year and a half. After a similar period at Berlin, he passed his state examination in pharmacy in 1863; but preferring chemistry and botany, he went to Heidelberg to work under Bunsen and Hofmeister. There he obtained his Ph.D. in June 1864, for a thesis entitled “Chlor–und Bromgehalt des Meerwassers”.

Soon afterward, a severe attack of pneumonia forced Brefeld to give up chemistry. During convalescence in Italy he studied art. On his return, he managed the family pharmacy for a short period, meanwhile beginning private researches on fungi. In 1868, financially assisted by his father, he went to the Botanical Institute at Halle to work with Anton de Bary. Two years later the Franco–Prussian was intervened, and Brefeld was drafted as an army pharmacist. During the siege of Paris the contracted typhoid fever, which proved nearly fatal. He was invalided home early in 1871 after devoted nursing by a French pharmacist. When fully recovered, he returned briefly to Halle. Thence, after short periods in Munich and at the Botanical Institute at Würzburg, he went in 1873 to Berlin, where he became Privatdozent in botany in 1875.

In 1878, shortly after becoming professor of botany at the Forest Academy of Eberswalde, near Berlin, Brefeld suffered a grave mishap. While examining a forestry class in chilly rain, he caught a severe cold, accompanied by ocular inflammation. This culminated in retinal detachment, glaucoma, and surgical removal of the left eye. He spent two years in Italy recuperating, again studying art. In the autumn of 1881 he resumed his researches, having appealed in vain to the Agriculture Ministry for an assistant because of his damaged eyesight.

In 1884 Brefeld became professor of botany at the Royal Botanical Institute and director of the botanical garden at Münster, where he spent fourteen very productive years. His work attracted international attention, and various foreign academies elected him to membership. He traveled in England, France, and Spain, meeting many scientists, including Pasteur, with whom he later corresponded. In 1896 he was appointed Geheimer Regierungsrat and in 1897 was made a corresponding member of the Berlin Academy of Sciences.

Brefeld married Elizabeth Godendahl, daughter of a Münster merchant, in 1896. Two years later he succeeded Ferdinand Cohn at Breslau as professor of botany and director of the Institute of Plant Physiology. In 1902, when Brefeld was sixty-three, his wife died shortly after the birth of their only child, Walter. His remaining eye now developed glaucoma, and in 1905 Brefeld became unable to teach; but with his assistant, R. Falck, he continued to work until increasingly defective vision forced his resignation in 1907.

Brefeld moved with his young son and housekeeper to Berlin, Where be became completely blind in 1910, following an unsuccessful eye operation. Thereupon he withdrew to a property he owned in Berlin-Lichterfelde. In 1918, wartime malnutrition compelled him to enter a Rhineland sanatorium until 1924, when he moved to a nursing home at Schiachtensee, near Berlin. He remained completely alert mentally until his death from a colonic disorder.

Brefeld’s blunt individuality and caustic wit were effective when used in defense of freedom of speech or for prescient warnings against the political philosophy that led Germany into World War I. His scientific reports, however, were sometimes needlessly polemic—a fault that his personal misfortunes, his single–minded attachment to mycology, and the lasting loyalty of his assistants helped to mitigate.

Brefeld’s first publication concerned a new species of Myxomycetes, Dictyostelium mucoroides (1869). After the war, he began those detailed investigations into the developmental history and systematic relationships of fungi that became his lifework. Part I of his Botanische Untersuchungen über Schimmelpilze (1872), respectfully dedicated to his teacher de Bary, described three fungal species of Zygomycetes, a subclass characterized by Brefeld himself. The preface states a fundamental tenet that was to govern all his work: “The developemetal history of a mold is deduced completely from the culture of the individual spore”.

A report on Penicillium, completed while Brefeld was at Würzburg, appeared in 1874. In Berlin he published his first monograph on the Basidiomycetes (1877). These works, which constituted Parts II and III of his Untersuchungen, reflect his changing views on the sexuality of fungal fruit bodies. Part IV (1881) included observations on various species of Zygomycetes and Ascomycetes, and on Bacillus subtilis, preceded by a section expounding methods he had developed since 1869 for microscopic observations of pure fungal cultures. The same volume reveals an open feud with de Bary, whose claim—eventually verified—that the higher fungi exhibit sexuality Brefeld henceforth denied. Thirty years later, he intransigently wrote: “It is a basic error to correlate fungal pleomorphy with sexuality in the higher fungi, which has been construed after the pattern of the algae, but in reality does not exist”. Meanwhile, he reacted unduly whenever criticisms of his work appeared in de Bary’s journal, the Botanische Zeitung.

Brefeld’s cultural methods (first outlined in 1874) stressed the heat sterilization of culture media, glassware, utensils, and instruments; precautions to exclude dust-borne contaminants; and use of sufficiently diluted inocula to permit single-spore transfers. He invented or adapted such useful devices as “capillary culture chambers” and the “hanging drop” (generally known as the Van Tieghem cell). As basal nutrient medium, he favored decoctions of fresh manure from a herbivore; but solid sterile dung, or bread soaked in dung decoction, prevented dispersal and facilitated study of growing cultures. Addition of gelatin to the fluid medium permitted freer manipulation of preparations under the microscope and reduced evaporation of the medium without altering its transparency or nutritive qualities.

On returning to work after losing his eye, Brefeld made thousands of cultures, employing the foregoing techniques, to demonstrate that parasitic fungi, such as the cereal smuts, might be grown saprophytically. He cultivated over twenty species of ustilago, as well as the potato blight fungus and other usually parasitic species. His observations led him to conclude that the yeasts, hitherto classified as “sprouting fungi”, were conidial forms of higher fungal genera. These findings were reported in Part V of the Untersuchungan (1883), Part VI, on certain Myxomycetes and Entomophthorales, followed (1884), under the final version of the main title, Untersuchungen aus dem Gesammigenbiete der Mykologie.

At Münster, Brefeld had two young assistants, G. Istvánffy and O. J. Olsen (later known as O. Sopp), for Parts VII (1888) and VIII (1889), which reported further studies on over 200 species of Basidiomycetes. De Bary was again attacked in Part VII. He had suggested that Brefeld’s views on the “sprouting fungi” were too sweeping and that yeasts were rudimentary forms of Ascomycetes.

F. von Tavel, and to a lesser extent G. Lindau, assisted Brefeld with Parts IX and X, on the Ascomycetes (1891), of which more than 400 species were studied. Work was resumed on the cereal smuts, over sixty species being cultivated on laboratory media. Growing “inexhaustible quantities” of specific fungi saprophytically, Brefeld investigated the mechanisms of infection, and the temporal and nidal variations in host susceptibility, in several smut diseases. These climactic efforts were reported in Parts XI and XII (1895).

Despite the many difficulties, domestic and administrative, that beset Brefeld in Breslau, Part XIII appeared in 1905, with Falck as co-author, describing the mechanisms of blossom infection by smut fungi and their natural modes of dissemination. In retirement, the totally blind mycologist dictated a recapitulation of his cultural methods and also reported miscellaneous earlier observations, published in Part XIV (1908). In Part XV (1912), he reverted mainly to smuts and smut diseases. A sixteenth part in manuscript was never published. Falck, in his obituary tribute, summarizes the contents of each part of the Untersuchungen.

Brefeld’s manifold contributions to microbiology included a cultural methodology that was far more precise than Pasteur’s and stimulated Koch to improve upon the gelatinized nutrient medium he is wrongly credited with having initiated. The indirect practical benefits to North America of Brefeld’s work on smuts, especially of wheat, are inestimable. His Untersuchungen, often termed the “Bible of mycology,” contains some errors of observation and interpretation, as well as unduly repetitive and vituperative passages; but the work is replete with classic observations, novel findings, and prophetic conjectures, recorded in colorful style. The accurate artistry of innumerable drawings on over 100 folio plates ensures the continuing reproduction of samples in mycology texts. Unfortunately, only fragments of his writings are available in English. Brefeld’s extraordinary experimental skill, combined with rare patience and complete dedication, inspired A. H. R. Buller to call him “one of the ablest botanists of the nineteenth century”.

BIBLIOGRAPHY

I. Original Works. The first seven pts. of Brefeld’s chief work, Botanische Untersuchungen…, were published between 1872 and 1888 in Leipzig, and the last eight pts. between 1889 and 1912 in Münster. The dates and titles are, under the general title Botanische Untersuchungen über Schimmelpilze, I, Zygomyceten (1872); II, Penicillium (1874); III, Basidiomyceten I (1877); IV, Culturmethoden… (1881); as Botanische Untersuchungen über Hefenpilze, V. Die Brandpilze I(1883); and, under the comprehensive title Untersuchungen aus dem Gesammigebiete der Mykologie, VI, Myxomyceten I. Entomophthoreen II (1884); VII, Basidiomyceten II (1888), written with G. Istvánffy and O. J. Olsen; VIII, Basidiomyceten III (1889); IX, Die Hemiasci und die Ascomyceten (1891), written with F. von Travel and G. Lindau; X, Ascomyceten (1891), written with F. von Tavel; XI, Die Brandpilze II (1895), written with G. Istvanffi; XII, Hemibasidii, Brandpilze III (1895); XIII, Brandpilze (Hemibasidii) IV (1905), and XV, Die Brandpilze und die Brandkrankheiten V (1912). Falck, in his obituary on Brefeld, lists twenty–six additional publications in various German scientific journals, the earliest being “Dictyostelium mucoroides, ein neuer Organismus aus der Verewandtschaft der Myxomyceten,” in Abhandlungen herausgegeben von der Senckenbergischen naturforschenden Gesellschaft, 7 (1869), 85–107.

Translations of works by Brefeld are “Recent Investigations of Smut Fungi and Smut Diseases”, trans. from Nachrichten aus dem Kulb der Landwirthe zu Berlin, nos. 220–222 (1888) by Erwin F. Smith in Journal of Mycology, 6 (1890), 1–9, 59–71, 153–164; and Investigations in the General Field of Mycology, Blossom Infection by Smus and Natural Distribution of Smut Diseases, pt. 13, written with R. Falck, trans by Frances Dorrance (n.p., 1912).

II. Secondary Literature. Obituaries are W. Brefeld, “Oscar Brefeld, ‘Ein Leben für die Mykologie’”, an unpub, memoir by his son (personal communication, Sept. 1967); R. Falck, “Oskar Brefeld,” in Botanisches Archiv, 11 (1925), 1–25; M. Kienitz, “Zum Gedächtnis. Dr. Oskar Brefeld, Professor der Botanik an der Forstakedemie Eberswalde in den Jahren 1.10.1878–1884”, in Zeitschrift für Forst-und Jagdwesen, 57 (1925), 709–711; F. Rosen, “Das pflanzenphysiologische Institut”, in Festschrift zur Feier des hundeerijährigen Bestehens der Universität Breslau (Breslau, 1911), see pp. 496–498; and O. Sopp, “Minnetale over prof. dr. Oscar Brefeld”, in Norske Videnskaps–Akademi i Oslo Årbok (1925), pp. 83–86.

Important references to Brefeld’s work are A. H. R. Buller, Researches in Fungi, 7 vols. (I–VI, London, 1909–1934; VII, Toronto, 1950; all repr. New York, 1958); A. De Bary, Comparative Morphology and Biology of the Fungi. Mycetozoa and Bacteria, Henry E. F. Garnsey, trans. (Oxford, 1887; repr. New York, 1966), pp. 256–257, 272, 295–297; M. Möbius, Geschichte der Botanik, Von der ersten Anfängen bis zur Gegenwart (Jena, 1937), pp.74, 102–106; and J. Ramsbottom, “The Expanding Knowledge of Mycology Since Linnaeus”, in Proceedings of the Linnean Society of London, 151 (1939), 280–367.

Claude E. Dolman