Flexner and Flemming

FLEXNER, Simon (born 1863), a prominent American microbiologist; graduated from the University of Louisville, then worked at Johns Hopkins University in Baltimore, as well as in Europe, at the universities of Strasbourg, Berlin, and Prague, and at the Pasteur Institute in Paris. From 1889 to 1899, he was a private docent in the department of pathological anatomy at Johns Hopkins University; from 1899 to 1903, a professor of pathology at the University of Pennsylvania; and finally, from 1903 to the present, he has served as director of the Rockefeller Institute for Medical Research in New York. Flexner’s main works relate to the pathology of intoxication by toxalbumins, the study of the biochemical composition of snake venom, experimental pancreatitis and fatty degeneration of tissues, cerebrospinal meningitis, poliomyelitis, and epidemic encephalitis. In 1905, Flexner was the first to propose and introduce into general medical use a serum against cerebrospinal meningitis, the application of which significantly reduced mortality from this disease. He studied the methods of transmission and spread of poliomyelitis and developed methods of treatment through the use of convalescent serum. Flexner is an honorary member of most European and American scientific societies. FLEMMING, Walther (1843–1905), a famous German histologist. He received his medical education in Göttingen, Tübingen, and Berlin, completing it in 1868 in Rostock; upon graduation, he studied zoology and histology under the guidance of F. E. Schulze and Semper. From 1871, Flemming was a prosector of anatomy under Henke in Rostock; from 1873, a professor of histology in Prague; and from 1876, a professor of anatomy in Kiel; he left the university in 1901. Flemming’s main works, which brought him wide renown, relate to the study of the fine structure of the cell: the structure of protoplasm and the nucleus, the process of karyokinesis (which he described in full detail for the first time and divided into phases), centrosomes, and direct division. He found a suitable object for this (salamander larvae) and developed a special technique for fixation (Flemming’s fluid) and staining. His works up to 1881 were summarized in the classic work 'Zellsubstanz, Kern und Zellteilung' (Leipzig, 1882), which initiated a new cytological period in histology; subsequent works appeared in 'Neue Beiträge zur Kenntniss der Zelle' (Archiv für mikroskopische Anatomie, Vol. XXIX, 1887, and Vol. XXXVII, 1891), as well as in a number of smaller articles. Among Flemming’s other works, one should note: studies on the histology of mollusks, on tissue regeneration, on the germinal centers of follicles, on the structure of cells in spinal ganglia, and a series of works on fatty and connective tissue. All of Flemming’s works are of a purely morphological nature, distinguished by extreme precision of observation, a critical attitude toward what was observed, and great caution in conclusions; they have entered science as a lasting asset. In this regard, Flemming is the best example of a cytologist-morphologist. Literature: W. Spee, 'Walther Flemming, sein Leben und Wirken', Anatomischer Anzeiger, Vol. XXVIII, 1906 (list of works).