Mat 30, 1913] 



SCIENCE 



811 



also with plants, stones and minerals. He 

 collected extensively, his herbarium which 

 he presented to the university contained 

 over 1,500 species, all determined by him- 

 self, and his mineralogical collection has 

 been described as "very fine and valuable" 

 and was purchased by the National Mu- 

 seum in Washington. But his chief collec- 

 tions were of animals, especially of such 

 as offered opportunity for microscopical 

 study. The quotation read a few moments 

 ago refers to his gathering of fishes — the 

 particular "fishes" in this case were the 

 Rhizopods. His monograph of this group 

 of unicellular animalcules appeared in 

 1879 as one of the quarto volumes of the 

 Hayden Survey, and contains a vast 

 amount of original observation and is illus- 

 trated by thirty plates, after his own draw- 

 ings of the living animals. Another ex- 

 tensive work was entitled "Flora and 

 Fauna within Living Animals, ' ' one of the 

 most important contributions to parasitol- 

 ogy we possess. It was published in 1851 

 by the Smithsonian Institution in Wash- 

 ington, and is illustrated by ten exquisite 

 copper plates, so skillfully engraved by 

 Oudet that they worthily reproduce the 

 author's beautiful drawings. 



The range of work we have already in- 

 dicated is sufficient to more than occupy 

 an able man, and the results published by 

 Leidy in the field of zoology proper would 

 alone suffice to assure his place among the 

 most distinguished investigators of Amer- 

 ica. His actual reputation, however, rests 

 at least in equal measure upon his achieve- 

 ments in vertebrate paleontology, which 

 received a richly deserved recognition 

 when the Geological Society of London 

 awarded him in 1884 the Sir Charles Lyell 

 medal. His monographs on American fos- 

 sil vertebrates laid the foundations of our 

 present knowledge, and first marked out 

 the way by following which Cope and 



Marsh and their younger successors have 

 attained distinction. Mention may be 

 made especially of the first memoir of the 

 series, "The Ancient Fauna of Nebraska, 

 a Description of Extinct Mammalia and 

 Chelonia from the Mauvaises Terres of 

 Nebraska," published in 1854 in the sixth 

 volume of the Smithsonian Contributions 

 to Knowledge. The wonderful Eocene de- 

 posits of the Bad Lands had not been long 

 known, and the collections available had 

 been hardly more than skimmings from the 

 surface. Leidy by the friendly coopera- 

 tion of the few collectors of the time was 

 able to inspect practically all the remains 

 which had been gathered. The plates are 

 superb lithographs drawn by the talented 

 Sonrel. In 1855 followed the memoir on 

 the Sloths, in 1865 on the Cretaceous rep- 

 tiles, and other memoirs in later years 

 (1869, 1873 and 1877). 



A special extraneous interest attaches to 

 Leidy 's paper on the extinct sloths, for it 

 includes a careful description of Megal- 

 onyx Jefersoni, the first remains of which 

 were discovered in Virginia and were de- 

 scribed by no less a person than Thomas 

 Jefferson at a meeting of the American 

 Philosophical Society on March 10, 1797. 

 The bones were soon after identified by 

 Dr. Caspar Wistar as not those of a car- 

 nivore, as thought by Jefferson, but of a 

 sloth. Casts of these bones were sent to 

 Cuvier, who studied them. I am told that 

 the originals, collected bj' Jefferson, are 

 now in the collection of the Academy of 

 Natural Sciences in this city. 



It happened that the study of vertebrate 

 paleontology in the seventies and eighties 

 of the last century was pursued with great 

 zeal, but also unfortunately with certain 

 rivalries, which aroused acrimonious feel- 

 ings, too often publicly expressed. Leidy 

 shrank from controversy and it is said that 

 rather than risk being entangled in dis- 



