an early period of his investigations to animals which had been somewhat neglected by naturalists, and the fruit of his studies among them appeared in his work upon "Myriapods and Fresh-Water Polypi." In this work he defined accurately for the first time the characteristics of the animals, and followed out some of the changes which are gone through by certain of the species at various ages. In 1835 M. Gervais was admitted as preparator into the laboratory of comparative anatomy of the Museum of Natural History, and a special direction was given to his studies. Professor de Blainville was preparing a grand work on the bony frame of living and fossil mammals; and the young naturalist, exerting his whole effort in assisting his master, attached himself with marked preference to researches on extinct species, of which he had the satisfaction of describing definitely not a few that had been hitherto unobserved or inadequately studied.
In 1841, according to Larousse's "Dictionnaire Universelle," after having spent ten years in the Museum, according to M. Blanchard, M. Gervais was called to the chair of Zoölogy in the Faculty of Sciences at Montpellier, where he successfully continued his researches; and here he prepared and published his great book on the living and fossil vertebrates of France ("Zoölogie et Paleontologie Françaises," 1841-52), which was regarded as in continuation of Cuvier's and Blainville's publications on the same subject. He became Dean of the Faculty in 1856; was chosen correspondent of the Institute; and, on the death of Gratiolet, in 1865, became his successor as Professor of Anatomy, Comparative Physiology, and Geology, in the Sorbonne. In 1868 he became Professor of Comparative Anatomy in the Museum of Natural History, "returning as master to the laboratory in which his early youth had been spent." In the collections of this institution he found subjects of a most interesting character which were still awaiting an historian; and applying himself to the tasks thus pointed out to him, he engaged in those researches which resulted in the publication of his excellent work on the fossil mammalia of South America. The remains of aquatic mammalia that lived in the ancient seas having been exhumed in enormous quantities, M. Blanchard continues, a general study of the Cetaceæ seemed to impose itself upon him as indispensable to the progress of an essential part of zoölogy. M. Gervais undertook this long and difficult study in co-operation with his friend Professor Van Beneden, of the University of Louvain, and after several years the fruit of their conjoint studies appeared as the "Osteography of Living and Fossil Cetaceans" ("Osteographie des Cétacés Vivants et Fossils").
M. Stanislas Meunier has given, in "La Nature," careful accounts of M. Gervais's principal writings, with estimates of their scope and value. The "Documents pour servir à la Monographie des Chiroptères Sud-Américains" ("Documents in aid of the Monography of the South-American Chiropteræ") included descriptions of many species
