tion of the leading naturalists of Philadelphia, and quickly brought him into communication with Cassin, Morton, Phillips, Bridges, Griddon, Gambel, Conrad, Vaux, Pickering, and other leading members of the Academy of Natural Sciences. Community of interests led to an intimate association with those gentlemen, and he was elected a member of the Academy in July, 1845.
His first published communication, entitled "Notes on White Pond, Warren County, New Jersey," was presented to the Academy in October of the same year, and so active from that time was his work in connection with the society that, at the annual election, in 1846, he was elected chairman of the Curators, a position which he has since uninterruptedly occupied. With characteristic modesty he has frequently declined the presidency of the society, and has contented himself with the quiet, unostentatious performance of the very important duties of chairman of the Curators. The respect and personal affection with which Dr. Leidy inspires every one brought into intimate communication with him, together with his practical good sense and knowledge of the needs of a large collection of objects of natural history, have enabled him to act with great efficiency in his office for the good of every department and interest of the society. He has been also a number of years chairman of the Library and Publication Committees.
Shortly after assuming his position in the university, Dr. Leidy edited an edition of Sharpey and Quain's "Anatomy," with a view to supplying the wants of his class while preparing a manual of his own. The latter was published in 1861, and for clearness and accuracy of statement and convenience of arrangement has not been equaled by any other elementary treatise on human anatomy in the English language.
Dr. Leidy's earlier scientific work was confined to no specialty. The whole field of Nature lay extended before him, and innumerable were the objects of interest which engaged his attention. Hence one is surprised to find how almost encyclopedic is Dr. Leidy's knowledge of natural history. Although he has published little or nothing upon either mineralogy or botany, his knowledge of both these sciences is rather that of one who devotes himself specially to them than that of the casual student. The pages of the "Proceedings" of the Academy for 1845 and 1846, however, indicate that his favorite field of research during that time was among the lower animal forms, and that his microscope was often brought into use. The anatomy of spectrum femoratum (Say), new species of entozoa, the mechanism which closes the wings of grasshoppers, the situation of the olfactory sense in the gasteropods, and new species of planarian worms, were among the subjects upon which communications were published in rapid succession during the first two years of his connection with the Academy.
In October, 1846, he recorded the occurrence of a species of trichina in the hog, and stated that he could perceive no distinction between
