on the extinct vertebrates of North America. His first paper on palae- 

 ontology was published in 1846, and his last in 1888, as the subject 

 occupied him for more than forty years. He laid, with the hand of a 

 master, the foundation for the palaeontology of the reptiles and mammals 

 of North America, and we know what a wonderful and instructive and 

 world-renowned superstructure his successors have reared upon his 

 foundation. It was this work that established his fame and brought 

 his honors and rewards. They who hold it to be his best title to be 

 enrolled among the pioneers of science in America are in the right, in so 

 far as the founder of a great department of knowledge is most deserving 

 of commemoration; but I do not believe it was his most characteristic 

 work. 



I can mention but one of the results of his study of American fossils. 

 He showed, in 1846, that this continent was the ancestral home of the 

 horse, and he sketched, soon after, the outline of the story of its evolution 

 which later workers have made so familiar. 



More than half his papers are on a subject which seems to me to 

 contain the lesson of his life. Like Gilbert White, he was a home 

 naturalist, devoted to the study of the natural objects that he found 

 within walking distance of his home, but he penetrated far deeper into 

 the secrets of the living world about him than White did, finding new 

 wonders in the simplest living being. In the intestine of the cock-roach, 

 and in that of the white ant, he found wonderful forests of microscopic 

 plants that were new to science, inhabited by minute animals of many 

 new and strange forms. His beautifully illustrated memoir on A 

 Flora and Fauna Within Living Animals is one of the most remarkable 

 works in the whole field of biological literature. Another memoir 

 gives the results of his study of the anatomy of snails and slugs. The 

 inhabitants of the streams and ponds in the vicinity of his home fur- 

 nished an unfailing supply of material for research and discovery, and 

 many of his publications are on aquatic animals. He finally became 

 so much interested in the fresh-water rhizopods that he abandoned all 

 other scientific work in order to devote his attention exclusively to these 

 animals. His results were published in the memoir on The Fresh- 

 water Rhizopods of North America. This is the most widely known 

 of his works. It is, and must long be, the standard and the classic 

 upon its subject. I have no time to dwell upon his work as the naturalist 

 of the home — his best and most characteristic work. Its lesson to 



24 



