# 1911 Encyclopædia Britannica/De Bary, Heinrich Anton

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​DE BARY, HEINRICH ANTON (1831–1888), German botanist, was of Belgian extraction, though his family had long been settled in Germany, and was born on the 26th of January 1831, at Frankfort-on-Main. From 1849 to 1853 he studied medicine at Heidelberg, Marburg and Berlin. In 1853 he settled at Frankfort as a surgeon. In 1854 he became privat-docent for botany in Tübingen, and professor of botany at Freiburg in 1855. In 1867 he migrated to Halle, and in 1872 to Strassburg, where he was the first rector of the newly constituted university, and where he died on the 19th of January 1888.
Although one of his largest and most important works was on the Comparative Anatomy of Ferns and Phanerogams (1877), and notwithstanding his admirable acquaintance with systematic and field botany generally, de Bary will always be remembered as the founder of modern mycology. This branch of botany he completely revolutionized in 1866 by the publication of his celebrated Morphologie und Physiologie d. Pilze, &c., a classic which he rewrote in 1884, and which has had a world-wide influence on biology. His clear appreciation of the real significance of symbiosis and the dual nature of lichens is one of his most striking achievements, and in many ways he showed powers of generalizing in regard to the evolution of organisms, which alone would have made him a distinguished man. It was as an investigator of the then mysterious Fungi, however, that de Bary stands out first and foremost among the biologists of the 19th century. He not only laid bare the complex facts of the life-history of many forms,—e.g. the Ustilagineae, Peronosporeae, Uredineae and many Ascomycetes,—treating them from the developmental point of view, in opposition to the then prevailing anatomical method, but he insisted on the necessity of tracing the evolution of each organism from spore to spore, and by his methods of culture and accurate observation brought to light numerous facts previously undreamt of. These his keen perception and insight continually employed as the basis for hypotheses, which in turn he tested with an experimental skill and critical faculty rarely equalled and probably never surpassed. One of his most fruitful discoveries was the true meaning of infection as a morphological and physiological process. He traced this step by step in Phytophthora, Cystopus, Puccinia, and other Fungi, and so placed before the world in a clear light the significance of parasitism. He then showed by numerous examples wherein lay the essential differences between a parasite and a saprophyte; these were by no means clear in 1860–1870, though he himself had recognized them as early as 1853, as is shown by his work, Die Brandpilze.
These researches led to the explanation of epidemic diseases, and de Bary’s contributions to this subject were fundamental, as witness his classical work on the potato disease in 1861. They also led to his striking discovery of heteroecism (or metoecism) in the Uredineae, the truth of which he demonstrated in wheat rust experimentally, and so clearly that his classical example (1863) has always been confirmed by subsequent observers, though much more has been discovered as to details. It is difficult to estimate the relative importance of de Bary’s astoundingly accurate work on the sexuality of the Fungi. He not only described the phenomena of sexuality in Peronosporeae and Ascomycetes—Eurotium, Erysiphe, Peziza, &c.—but also established the existence of parthenogenesis and apogamy on so firm a basis that it is doubtful if all the combined workers who have succeeded him, and who have brought forward contending hypotheses in opposition to his views, have succeeded in shaking the doctrine he established before modern cytological methods existed. In one case, at least (Pyronema confluens), the most skilful investigations, with every modern appliance, have shown that de Bary described the sexual organs and process accurately.
It is impossible here to mention all the discoveries made by de Bary. He did much work on the Chytridieae, Ustilagineae, Exoasceae and Phalloideae, as well as on that remarkable group the Myxomycetes, or, as he himself termed them, Mycetozoa, almost every step of which was of permanent value, and started lines of investigation which have proved fruitful in the hands of his pupils. Nor must we overlook the important contributions to algology contained in his earlier monograph on the Conjugatae (1858), and investigations on Nostocaceae (1863), Chara (1871), Acetabularia (1869), &c. De Bary seems to have held aloof from the Bacteria for many years, but it was characteristic of the man that, after working at them in order to include an account of the group in the second edition of his book in 1884, he found opportunity to bring the whole subject of bacteriology under the influence of his genius, the outcome being his brilliant Lectures on Bacteria in 1885. De Bary’s personal influence was immense. Every one of his numerous pupils was enthusiastic in admiration of his kind nature and genial criticism, his humorous sarcasm, and his profound insight, knowledge and originality.
Memoirs of de Bary’s life will be found in Bot. Centralbl. (1888), xxxiv. 93, by Wilhelm; Ber. d. d. bot. Ges. vol. vi. (1888) p. viii., by Reess, each with a list of his works; Bot. Zeitung (1889), vol. xlvii. No. 3, by Graf zu Soems-Laubach.  (H. M. W.)