242 STUDY OF BRAINS OF SIX EMINENT SCIENTISTS AND SCHOLARS. 



uating in 1844, and practising thereafter for about two years. Leidy was not long, 

 however, in recognizing that his true vocation lay in the untrodden domains of biol- 

 - ogy. During a long and active career he not only developed many new facts in 

 zoology and comparative anatomy but he described many new forms of life, correlated 

 the existing facts, deduced new laws therefrom and, in short, did the chief pioneer 

 work in formulating the laws and fundamental principles of a systematic science of 

 biology. While yet a student Dr. Leidy, by his skill in dissecting, had impressed 

 Professor Hornor most favorably and he was, therefore, shortly after his graduation, 

 appointed to the position of prosector to the chair of anatomy. In the summer of 

 1845 Dr. Leidy was elected a member of the Boston Society of Natural History, a 

 great compliment for so young a man, and a few weeks later he was elected to the 

 Academy of Natural Sciences of Philadelphia, with which institution his name was 

 inseparably connected until the day of his death. Through the opportunities for ad- 

 vancement liberally afforded by this society, he was enabled to accomplish the scien- 

 tific work of his life. He was chairman of its board of curators during the last forty- 

 four years of his life. In 1848 and 1849 Dr. Leidy accompanied Dr. Hornor and Dr. 

 George B. Wood on visits to Europe, affording him not only the opportunities of see- 

 ing the great museums of Europe under most pleasant auspices, but also of making 

 the acquaintance and acquiring the friendship of such distinguished anatomists and 

 physiologists as Owen, Majendie, Milne-Edwards, Hyrtl, Johannes Milller, and many 

 others. 



At the age of thirty he succeeded Dr. Hornor as professor of anatomy in the Uni- 

 versity of Pennsylvania. This position he held with the most distinguished success 

 till his death, a period of nearly forty years. As a teacher of anatomy, and as director 

 of the Biological Department of the University since its establishment in 1884, Joseph 

 Leidy attained his undisputed preeminence because his knowledge of human anatomy 

 was supplemented by familiarity in detail with the anatomy of every phase of animal 

 life from the amoeba to the higher mammalia. He possessed a masterly ability to so 

 present anatomic facts that this ordinarily dr}' and difficult subject became compara- 

 tively easy to master, chiefly because Leidy knew how to simplify his subject matter 

 and convey it to others. His writings, comprising nearly 600 treatises, are equally 

 notable for lucid expression, simplicity of presentation and accuracy of observation, 

 and his book on Human Anatomy became the standard treatise in most medical 

 schools. 



Joseph Leidy's scientific work embraced many fields : Biology in all its branches, 

 geology, mineralogy and botany, — in short the natural sciences as a whole. For an 

 explicit description of these achievements the reader is referred to the more thorough 



