Guilliermond, Marie Antoine Alexandre

(b. Lyons, France, 19 August 1876; d. Lyons, 1 April 1945)

botany.

Born into a family of physicians in which science was held in esteem, Guilliermond experienced the premature death of his father and several years later of his mother, who had been remarried to a physician. Sensitive and shy, he wished to teach and conduct research. His teachers were Maurice Caullery, Eugène Bataillon, and, in cryptogamy, Louis Matruchot. His teaching career was brilliant: beginning as a lecturer in agricultural botany at the Faculté des Sciences in Lyons, he went to the University of Paris in 1913 as lecturer in botany at the Faculty of Sciences and in 1935 succeeded Pierre Augustin Dangeard to the chair of botany at the Sorbonne. Much tried by France’s military misfortunes, he fell ill and retired in 1942. He died three years later. He had belonged to the Académie des Sciences since 1935.

Guilliermond’s brilliant investigations were conducted in two profoundly different areas requiring different mental orientations. His first works dealt with lower organisms: blue-green algae (cyanophyceae), bacteria, and especially yeasts, to which he devoted his doctoral thesis, Recherches cytologiques sur les levures et quelques moisissures à formes levures (1902). Were yeasts, as Oscar Brefeld held, more highly evolved forms of fungi? It was believed that they possessed a primitive structure with diffuse chromatin, but Guilliermond’s studies, which form the basis of our scientific knowledge of the yeasts, established as well the indisputable presence of a nucleus and its division at the time of budding. At first he thought the nucleus divided by amitosis. Later, progress in technique permitted him and his students to demonstrate that mitosis was in fact taking place. He also recognized the vacuoles and their content, which is precipitable in metachromatic corpuscles.

It was undoubtedly in the field of the sexuality of the yeasts that Guilliermond made the greatest progress: he established the occurrence of isogamous copulation before the formation of the ascus (Schizosaccharomyces octosporus) and of heterogamous copulation (Zygosaccharomyces chevalieri). He detected the copulation of the ascospores of various Saccharomyces, which allowed him to distinguish between haplobiontic and diplobiontic yeasts. Researches on the filamentous Endomycetaceae revealed analogous processes in this family and permitted the formulation of a classically accepted hypothesis regarding the phylogeny of the yeasts.

Guilliermond’s studies on the formation of the ascus among the higher Ascomycetes yielded important results. For example, through the tiny Pezizaceae Humaria rutilans, which possess the largest chromosomes among the fungi, he was able to demonstrate the characteristics of three successive mitoses of the ascus: heterotypic, homeotypic, and typical. Along the same lines, his research on the cytology of bacteria and especially of the Cyanophyceae contributed to the establishment of the then classically accepted type of these cells. (The electron microscope has since revealed the inaccuracy of this type.)

Because the yeasts provided the greatest continuity to Guilliermond’s first group of investigations, as a complete botanist he wished to become acquainted with the greatest number of forms. It was as a systematist that he published Les levures (1911) and later drew up the tables of yeasts in the Tabulae biologicae.

The second area of Guilliermond’s work is completely different. In the period in which physicochemical biology was actively developing, he wished, as a plant cytologist, to establish a close contact with animal cytology. His researches therefore dealt with the morphological constituents of the cytoplasm.

It had been known since 1910 that the chondriosomes, or mitochondria, consisting of a lipoprotein complex much richer in lipids than is cytoplasm, must play an important role in secretory phenomena. Also known was the importance of the vacuole system for cellular physiological phenomena. Through various means, such as plasmolysis, vital stains, mitochondrial techniques, and the ultramicroscope, the attempt could be made to answer a series of questions: Are there organelles other than the vacuoles which can arise de novo in the cell? Is it possible for the amidon to be formed not in the plasts but in the cytoplasm and even in the chondriosomes? What is the significance of the Golgi apparatus, revealed by silver stains, which seems to be attached sometimes to the vacuome, sometimes to the chondriome, and sometimes to be an autonomous formation?

Since the electron microscope did not then exist, the ultramicroscope presented the cytoplasm as a homogeneous gel, and these problems were approached in situ in the cell (and often in the living state). It is then possible to understand how courageous was Guilliermond’s research and how valuable the results obtained—for example, affirmation that only the vacuoles can be formed again. Furthermore, the attraction that this research held for many students provided Guilliermond with an excellent group with which to pursue this work.

BIBLIOGRAPHY

Works by Guilliermond include Recherches cytologiques sur les levures et quelques moisissures à formes levures (Lyons, 1902), his doctoral diss.; “Remarques sur la caryocinèse des Ascomycètes,” in Annales mycologici, 3 (1905), 344; “Recherches cytologiques et taxinomiques sur les Endomycétacées,” in Revue générale de botanique, 21 (1909), 353; “Nouvelles observations sur la sexualité des levures,” in Archiv für Protistenkunde, 28 (1912), 52; Traité de cytologie végétale (Paris, 1933), written with G. Mangenot and L. Plantefol; Précis de biologie végétale (Paris, 1937), written with G. Mangenot; and Introduction á l’éde de la cytologie, 3 vols. (Paris, 1938).

Lucien Plantefol