OF ARTS AND SCIENCES : MAY 28, 1867. 301 



his father's farm, -^ a few winter months to the common schooh When 

 only fifteen years old he toolv the whole charge of the farm, but still 

 managed to secure a few months for study, so that, after a year in an 

 academy, he was able to enter Harvard College, in 1821 ; although, as 

 he tells us, so ill prepared that his college life was a continual struggle 

 to overcome the barriers which straitened means had placed between 

 himself and the things he aspired to. By severe industry and strict 

 economy he made his way, both as to livelihood and learning, and was 

 graduated with respectable rank. He became a private tutor in Mary- 

 land, and at the same time began the study of medicine, which he 

 completed in Boston, passing a year in the Massachusetts General 

 Hospital, as house student, and taking his degree of M. D. in 1830. 

 His struggle with poverty was not yet ended. He had to undertake 

 various tasks, the most Herculean of which was the preparation of the 

 catalogue, in four large folio volumes, of the fifty thousand pamphlets 

 in the library of the Boston Athenceum. But he always found some 

 time for the scientific studies in which he soon became eminent. His 

 taste for Natural History, which had begun to show itself in college, 

 especially in the way of botany, now took its particular bent. His 

 first scientific memoir, communicated to the Boston Society of Natural 

 History, — of which he was one of the earliest, and always one of the 

 most efficient members, — was on the Oicindelce of Massachusetts. 

 The next was a monograph of the species of the genus Pupa, found 

 in the United States, in which he points out how their classification 

 might be improved by the use of the microscope. In 1841 he read 

 before the same society a paper on the geographical distribution of the 

 shells of Massachusetts, dealing with considerations which had at that 

 time attracted little attention. He showed the proportion between the 

 marine and the fresh-water species (forty-two of the latter to two hun- 

 dred and three of the former), and stated that, on a careful comparison, 

 he was unable to satisfy himself that any of the fresh-water species 

 were common to the Old World and the New; and, finally, he indi- 

 cated the fact that Cape Cod forms an impassable barrier to the exten- 

 sion of many marine species. 



But the most considerable of his earlier contributions to science was 

 his Report on the Invertebrate Animals of Massachusetts, chiefly de- 

 voted, however, to the Mollusca. Up to this time there had been few 

 if any attempts at so complete a survey of the zoology of any partic- 

 ular region of the United States. This fills a volume of 400 pages. 



