838 The American Naturalist. [October, 
as reports of the respective surveys with which he was con- 
nected. 
The various investigations thus opened were continned 
through the succeeding years. His collections continued to 
grow in spite of reduced means. He refused even to sell por- 
tions for which he was offered liberal sums, and, at the cost of 
personal discomfort, held on to them and made his home, for 
much of the time, in the midst of them, having sold his resi- 
dential house but kept his museum. 
In 1878 he purchased the rights of the proprietors of the 
AMERICAN NATURALIST and removed it to Philadelphia. Pro- 
fessor Packard, one of the original proprietors, cooperated with 
him in the editing of it for some years, and he was also as- 
sisted by various eminent specialists. In this journal numer- 
ous articles of all kinds, including reviews and editorial com- 
ments, were published by him. His last words appeared in 
numbers issued after his death, the leading article in the 
number for June having been written shortly before his death ; 
it treats of the remarkable mammals of South America, known 
as Toxodontia. : et 
In 1886 he received an appointment to a chair in the Uni- 
versity of Pennsylvania and became professor of geology and 
paleontology. Such a man naturally awakened the interest of 
apt pupils, and he was a facile and entertaining lecturer. 
From the stores of a rich memory he could improvise a dis- 
course on almost any topic within the range of his varied 
studies. His views were so much in advance of those in any 
text-book that for his own convenience, no less than for the 
benefit of his pupils, he felt compelled to prepare a “Syllabus 
of lectures on geology and paleontology,” but only “ Part HI, 
Paleontology of the Vertebrata,” was published. It appeared 
in 1891, and is still a valuable epitome of the classification of 
the vertebrates, recent as well as fossil, giving in dichotomous 
tables the essential characters of all the groups above families 
and also the names of all the families. His own industry and 
investigations did much to render this antiquated in even six 
years, and a new edition of work became necessary. ‘‘ Upon 
the Tuesday preceding his death he sent to the press an ela- 
