LEIDY 695 LEIDY long period. He believed that similar experi- ments on warm-blooded animals might in- crease the number of viable cancerous ele- ments, and the facts of his experiments proved that cancer might be inoculable. A note- worthy feature in his work in anatomy was an attempt to anglicize anatomical nomencla- ture. Among the unrecorded discoveries one deserves mention here. Leidy stated that the discovery of the tactile corpuscle on the nerves of the finger is his own. He also frequently alluded to his having obsen'ed the amoeboid movements in the white corpuscles, but he interpreted them to be pathological and hesi- tated in recording his discover}'. It is stated that Leidy considered, his failure to record this fact one of the greatest mistakes of his life. In 1886, under the cover of a short article entitled "Researches on Parasites and Scor- pions," Leidy expressed the opinion that hook- worm might perhaps be the cause of perni- cious anemia in the United States. This was twelve years before the investigations by Stiles and Ashford apprised the world of the medical importance of this parasitic infection. Leidy's work as anatomist, botanist, miner- alogist, paleontologist, zoologist and anthro- pologist is crowned by a total of nearly 600 publications. His works are essentially rec- ords of facts often new and of the greatest scientific importance. In medicine -he was primarily an anatomist and helminthologist and his writings on these subjects alone num- ber over 150. Some of his most important contributions are: "Researches into the com- parative structure of the liver," 1848; "Inter- maxillary bone in the embryo of the human subject," 1849; "An elementary treatise on human anatomy" (First edition, 1861, 2nd edition, 1889) ; "Intestinal worms," 1888. It is interesting to note that in 1848 he made the discovery of the presence of eyes in a species of Balanus, leading Darwin to look for them in other members of this group. Leidy was one of the group of four dis- tinguished true naturalists who have done most for the introduction of natural science into America — namely. Louis Agassiz, Spencer F. Baird, James D. Dana and Joseph Leidy. He was singularly interested in the very lowest forms of animal life and he wrote many short papers and in addition published a magnifi- cent monograph on "Rhizopods as they occur in all fresh waters of the country from the Atlantic border to an altitude of 10,000 feet in the Rocky Mountains," 1879. This work is beautifully illustrated with forty-eight large plates in color from Leidy's own exquisite drawings. In the domain of paleontolog}', and particularly vertebrate paleontology', his con- tributions were so brilliant that "they entitled him to be considered as the equal of any paleontologist produced by this country or Europe." His first paper on this subject ap- peared in 1847, "The fossil horse of America." Among the more prominent contributions to this subject are: "Ancient fauna of Nebras- ka," 1853; "Memoir of the extinct sloth tribe of North America," 1855 ; "Cretaceous rep- tiles of the United States," 1865 ; "Description of vertebrate remains from the phosphate beds of South Carolina," 1877. For many years Leidy was the only Ameri- can naturalist who devoted considerable time to the study of animal parasites and he col- lected many specimens and made valuable drawings illustrating new genera and species. This material has been arranged and edited by Dr. Joseph Leid}', Jr., a nephew of Leidy, under the title "Researches in helminthology and parasitology, with bibliography of his con- tributions to science," published by the Smith- sonian Institute in 1904. It embraces 281 pages and contains the life work of Dr. Leidy in parasitological and helminthological re- search arranged chronologically from 1846 to 1891. Perhaps the most important single con- tribution to helminthologN' is "A synopsis of entozoa and some of their ectocongeners," 1856, which was the first publication of its kind to appear in America. In this synopsis are contained 100 new species identified and named by Leidy, and reference is made to seventy-two known genera and species which he had encountered in a great variety of hosts. Early in April, 1891, he began to feel the strain of hard work and frequently had to sit down and rest during a part of his lectures. On Thursday, the twenty-eighth, he took to his bed and on April 30th he gradually lapsed into unconsciousness and died. Thus termi- nated the career of a man whose noble and unfailing devotion to duty gave the world a plentiful harvest of discoveries. Dr. Joseph Leidy was a man of most charm- ing personality. He enjoyed the society of his friends and was universal!}' beloved by his students who appreciated his instruction and marveled at his wonderful skill with the cray- on. Savants and students mourned his loss and gave glowing tribute to his memory. A statue to his memory stands by the City Hall in the shadow of William Penn. On the western slope of the Rocky Mountains in Wy- oming stands Mount Leidy, so christened by Dr. F. V. Hayden, the explorer and geologist. In the Luray Caverns of Page County, Vir- ginia, is a giant column and a stalactite dedi-
