(b, Port-au-Prince, Haiti, 31 July 1823; d. Meudon, France, 25 July 1899) biology.
Balbiani’s father, German by birth but of Italian descent, married a French Creole and went to Haiti to set up a banking firm. While still young, Balbiani was sent to Frankfurt am Main, and about 1840 he went to Paris to finish his studies, his mother having settled there. For a time Balbiani attended law school, but he was soon attracted by the natural sciences as they were being taught at the Muséum National d’Histoire Naturelle by de Blainville.
Balbiani became licencié és sciences naturelles in 1845 and docteur en médecine on 30 August 1854. His thesis, “Essai sur les fonctions de la peau considérée comme organe d’exhalation, suivi d’expériences physiologiques sur la suppression de cette fonction,’ was on a far higher level than the usual medical thesis.
His financial situation made it possible for Balbiani not to practice medicine, but to devote himself entirely to microscopic studies. As early as 1858 he communicated the first results of his research to the Academy. Balbiani founded the Societe de Micro–graphic and was a faithful member of the Societe de Biologic and the secretary of the Journal de physiologie. He was already well known in 1867, when Claude Bernard, who often praised him, asked him to direct the histological research at the laboratory of general physiology at the Museum. On 13 February 1874 he became professor of embryogeny at the College de France, a post he held for the rest of his life.
Balbiani’s work was extensive. His early research concerned protozoa, which at the time were subject to various interpretations. Some naturalists, following Ehrenberg, considered the infusoria as complete organisms with differentiated groups of organs. Others, such as Dujardin, saw in the protozoa only a mass of “sarcoda” without any organization whatever. These extreme views eventually were reconciled, but it is not possible to consider them here without outlining the history of protozoology. Balbiani discovered sexual reproduction in the ciliata, a finding that aroused much controversy until BUtschli confirmed Balbiani’s research and gave it its true interpretation. While studying the binary fission of the infusoria, Balbiani set forth its laws in 1861. This work led him to perform genuine microsurgical experiments that enabled him to specify the role of the nucleus. He also introduced the technique and the term “merotomy.”
Balbiani’s research on the formation of the sexual organs of the Chironomus demonstrated that the sexual cells derive directly from the egg and are differentiated before the blastoderm appears—and that consequently they precede the individual itself. This essential fact was later observed in other species and eventually was responsible for the general theory of the autonomy of the germ cell. Notice should also be made of Balbiani’s investigations on the reproduction of aphids and of his work on pebrine, the disease of the silkworm that later attracted Pasteur’s attention.
Balbiani is known eponymously through his research on cytoplasmic inclusions. He described in the yolks of young ovules a special formation that Milne–Edwards called the Balbiani vesicle (1867). This had already been pointed out by Julius Carus (1850) under the name “vitelline nucleus,” but Henneguy proposed calling it “corps vitellin de Balbiani” (1893). This body, interpreted by turns as a derivative of the centrosome or as an equivalent of the chondriome, has received new attention with the development of the electron microscope.
A solitary worker, Balbiani did not seek recognition through his lectures at the Collége de France. His publications were numerous, and with Ranvier he founded Archives d’anatomie microscopique, which is still published.
L. F. Henneguy has written two works that provide additional information on Balbiani; Leçons sur la cellule (Paris, 1896), and “Balbiani, E. G—Notice biographique,” in Archives d’anatomie microscopique, 3 (1900), i–xxxi, with a complete bibliography of Balbiani’s publications and a portrait.