1897.] . A Chapter in the History of Science. 851 
common characteristics of the three groups last mentioned— 
especially the structure of the brain and the development of 
the posterior cornua of the ventricles as well as calcarine sulci 
—justify the old order Primates. Nevertheless an important 
character was first appreciated in the composition of the podial 
bones, and fresh insight was obtained into the relations of 
ancient types. ; 
I can only name a few more of Cope’s discoveries in this 
connection. One was the generalization of “ trituberculy,” or 
the original development of three tubercles to molar teeth, 
and that subsequent modifications of the corresponding teeth 
were based on this original plan. Another was the remarka- 
ble Phenacodus of the Eocene, which was considered to be 
nearly in a line of descent for the Ungulates as well as the 
series culminating in man and which led him to the concep- 
tion of the taxeopodous group. 
The past history and genealogy of the Camels and their 
relations were likewise elucidated. In the present epoch only 
two nearly related types exist separated by half the globe— 
the true camels of central and northern Asia and the llamas 
of the Peruvian Andes. Cope revealed numerous species from 
various Tertiary beds and showed that the type was originally 
richly developed in America. 
VL 
Paleontology, from more than one point of view, may be di- 
vided into Invertebrata and Vertebrate. The subjects of the 
former are generally to be found in an approximately com- 
plete condition so far as the exterior is concerned, and early 
attracted the attention of investigators, often little familiar with 
recent zoology, and received names. The subjects of the lat- 
ter—especially the higher types, as mammals, birds and rep- 
tiles—are rarely found, except in a fragmentary condition. 
Special knowledge of osteology, even to its minutest details, is 
requisite to successfully deal with such remains. Consequently 
* Prof. Osborn in a recent letter has justly remarked, that ‘‘in the mammals I 
hardly feel you do Cope sufficient justice, his work has been so potent.” The 
exigencies of time and space alone prevented me from doing that justice, and I 
may remedy that defect later. 
