(b. Liège, Belgium, 1 January 1869; d. Brussels, Belgium, 27 December 1930)
Brachet was the only son of Auguste Brachet, an industrialist, and Louise Despae. A shy, sensitive, and self-contained child, he was a mediocre student in elementary school, and later said that his last years in secondary school reduced him to intellectual torpor. Having decided to study medicine, he entered the University of Liège and at once came under the influence of its celebrated professor of zoology, Edouard Van Beneden, whose lectures awoke young Brachet’s enthusiastic interest in the form and embryonic development of animals and man. At Van Beneden’s invitation, Brachet worked in the zoology laboratory in 1887–1888, learning the techniques of biological research. Thereafter, while still a medical student, he became histological preparator in the laboratory of Auguste Swaen, professor of anatomy. There Brachet began research on the development of the long bones of birds, which resulted in his first scientific publication, a monograph that appeared in 1893. In 1894 he was granted the M.D. by the University of Liège. About this time, at Swaen’s suggestion Brachet, in spite of his youth, boldly attacked some of the most difficult problems in vertebrate embryology—the earliest development of the liver and pancreas, and of the diaphragm and the pleuro-peritoneal cavity. He published these studies in various French and German scientific periodicals from 1895 to 1897.
When Brachet received his medical degree at the age of twenty-five, his parents wished him to practice medicine and even furnished an office for him, but by this time he had become thoroughly committed to morphological research. Winning a government traveling fellowship, he went to the University of Edinburgh, a famous center of human anatomy and the art of dissection; then to the laboratory of Ernst Gaupp at Freiburg im Breisgau to study the embryology of the head; and finally to Gustav Born at Breslau, where he learned the important new method of constructing enlarged models of embryos and their internal structures by the wax-plate method devised by Born. In Born’s laboratory he also observed newly introduced procedures of experimental embryology, by which Born and other embryologists were beginning to analyze embryonic development by excising parts of early embryos (chiefly of frogs and salamanders), transplanting limb buds, and producing local damage in the ovum and in early embryos.
After Brachet’s return to Liège in 1895, as assistant in anatomy, he collaborated with Swaen in Studies involving the whole vertebrate group, seeking to compare the early development of the heart, blood vessels, and urinary organs in mammals with that in the lower vertebrates (fishes and amphibians), where the pattern often is simpler and more comprehensible.
This broadened experience in comparative morphology turned Brachet’s attention to the earliest stages of development—the first cleavage of the fertilized ovum, the early differentiation of the embryonic area, and the beginnings of the head and trunk. These phenomena, complex and obscure in the higher animals, are susceptible of analysis by comparison with simpler processes of the same nature in lower vertebrates and in the invertebrates. For example, there is a well-known stage when the embryo has the form of a hollow ball so deeply indented at one point that the indented region coats the inside of the outer wall and the embryo is thus a two-layer sphere with an opening to the outside, the blastopore. The region of the blastopore becomes the active center of development of the embryonic body. In the vertebrates, however, the gastrula stage is so modified that it is recognizable only with difficulty. Brachet made notable contributions to the solution of this problem.
Another and even more recondite set of problems includes such questions as the extent to which embryonic structures are laid down in the undivided ovum, and the relation of the first planes of its cleavage to the axis of symmetry of the embryo. Such problems as these are to be solved partly by descriptive studies, partly by experiment. Brachet devoted himself to them for the rest of his life, by his own researches and those of the numerous advanced students who came to work with him. To the elucidation of these problems he brought the great variety of insights and methods he had gained at several centers of biological research. Among his most important studies at this time was an analysis of gastrulation in amphibians, in which he pointed out the similarity of this process to that of more primitive animals.
In 1900 Brachet was promoted to the post of chef des travaux pratiques, i.e., director of the students’ laboratory work, from which the next step would be to a professorial chair. No such vacancy was likely to occur soon in Liége, however, and when the chair of anatomy at Brussels became vacant in 1904 Brachet, with Van Beneden’s warm support, was appointed professor of anatomy and embryology, and director of the Institute of Anatomy of the University of Brussels.
Soon after he settled at Brussels, Brachet married Marguerite Guchez, a gifted student whose devotion and talents freed him from domestic concerns and allowed him to attack with undivided attention the tasks of building up the anatomy department, conducting his own intricate investigations, and guiding the numerous research students who came to his laboratory. The Brachets had two children, one of them the distinguished biochemist Jean Brachet.
At this time Brachet’s experimental work was directed chiefly to analyzing the inherent capacities of the egg cell and the way in which these potentialities of future development become localized in the embryo. For example, by pricking one of the two cells into which the fertilized ovum first divides, or similarly damaging one or another region of an embryo a few days old, he could discover the rate at which the embryonic cells differentiate into organ-forming areas. Brachet also devoted much time to the study of ova, chiefly of the frog, into which, by experimental treatment, he caused more than one sperm cell to enter, with resulting abnormalities of development that threw light on the normal process. He was one of the first to confirm the possibility of causing unfertilized ova to develop parthenogenetically by mechanical stimulation, and he pioneered in experimental attempts to cultivate the mammalian embryo (rabbit) in vitro.
The results of his varied and persistent investigations have become integral to today’s biological thought. It is to Brachet, perhaps more than to any other biologist of his time, that we owe our understanding that the fertilized egg cell, of whatever animal species, is neither a diminutive model that has only to unfold and enlarge in order to become an adult (preformation) nor an undifferentiated mass to be transformed by some mysterious force into adult tissues and organs (epigenesis) but, rather, a packet of living materials endowed with potentialities of growth and differentiation under inherent physical and chemical influences.
When World War I broke out, Brachet was in France, at a seaside laboratory in Roscoff, Brittany, and was not able to return to Brussels. He was invited to join the Medical Faculty of the University of Paris as adjunct professor of anatomy and embryology. On frequent trips to the Belgian front he gave anatomical instruction to the hospital surgeons. A highly successful series of special lectures at the Collége de France led to publication of an important book embodying Brachet’s findings of the previous decade, L’oeuf et les facteurs de l’ontogénése (1917).
After the war Brachet returned to Brussels, bearing with him the high regard of French colleagues, a regard soon expressed by corresponding membership in the Institut de France and an honorary doctorate from the University of Paris. Resuming his chair at Brussels, he published a valuable textbook, Traité d’embryologie des vertébres (1921). After the death of Van Beneden he assumed the editorship of the influential journal Archives de biologie. Always working on the fundamental problems of the organization of the ovum, the nature of fertilization, and the pattern of segmentation and early embryonic differentiation, he had at his side a succession of young biologists who, inspired hy his enthusiasm and intellectual force, went on to become professors of anatomy, embryology, or zoology in universities of Belgium, France, and Portugal. From 1923 to 1926, Brachet was rector of the University of Brussels. In the winter of 1928/1929 he made a successful lecture tour of the United States.
I. Original Works. Among Brachet’s writings are L’oeuf et les facteurs de l’ontogénèse (Paris, 1917) and Traité d’embryologie des vertèbres (Paris, 1921).
II. Secondary Literature. Works on Brachet are A. Celestino da Costa, “L’oeuvre embryologique d’Albert Brachet,” in Bulletin de la Société des Sciences Naturelles, 11 (1932), 179–220, with a list of Brachet’s publications; A. M. Dalcq, “Albert Brachet, 1869–1930,” in Florilège des sciences en Belgique (Brussels, 1968), pp. 991–1013, with a portrait; Giuseppe Levi, “Commemorazione del socio straniero, Albert Brachet,” in Rendiconti della Reale Accademia dei Lincei, 14 (1931), 382–393, with a list of Brachet’s publications; and H. de Winiwarter, Notice d’Albert Brachet (Brussels, 1932), with a portrait and list of publications.
George W. Corner