46 
of each of these authors. As widely apart 
‘in their personal characteristics and meth- 
ods of work, as it was possible to be, they 
were nevertheless the founders of American 
paleontology: lLeidy, a pre-evolutionist 
-and an exact descriptive writer, with little 
power of generalization; Marsh, a genius 
for the appreciation of the most important 
problems in evolution, with clearness as a 
writer, unrivaled talent as a collector and 
great powers of exact description, without 
.marked originality in the invention of hy- 
potheses ; Cope on the other hand a philoso- 
pher, fertile in hypotheses, a road-breaker in 
classification, hasty in description and with 
indomitable capacity for work. The com- 
paratively recent death of these three great 
men has totally changed the conditions of 
paleontology in this country, it now attracts 
-a large number of students and has spread 
through our institutions. Whereas twenty- 
three years ago paleontology was exclu- 
sively in the hands of Marsh and Cope, we 
now find workers in the National Museum, 
the Yale Museum, at Princeton, the Amer- 
ican Museum of Natural History, the Car- 
negie Museum of Pittsburg, and the Field 
Columbian Museum of Chicago, also in the 
Universities of Chicago, Kansas, Nebraska, 
Minnesota and Colorado. Explorations are 
now conducted on a most extensive scale, 
the peculiar American methods of work hay- 
ing been carried by two parties as far as 
Patagonia with remarkable results. 
Before describing the work of the Amer- 
ican Museum which is quite characteristic 
of the field at large, I want to speak of the 
philosophical development of this science. 
The wise and oft-quoted remark of Hux- 
ley’s, that the only difference between a 
fossil and a recent animal is that one has 
been dead longer than the other, is the epit- 
ome of the present attitude of our science. 
Huxley himself slowly reached this conclu- 
sion. After devoting the earlier years of 
his life to marine zoology, he shrank from 
SCIENCE. 
[N. S. Von. XIII. No. 315. 
accepting a post in the School of Mines, 
because it necessitated his centering his re- 
search upon extinct animals. Yet he be- 
came the Nestor of modern vertebrate 
paleontology, the first to thoroughly apply 
the principles of evolution as a means of 
interpretation of extinct forms. A fossil is 
still a synonym for dryness, and Huxley’s 
preconceived prejudice, which was trans- 
formed into a passionate devotion for fossils, 
represents a popular error, which I trust I 
shall succeed in fully dissipating this after- 
noon; in fact, the chief burden of my song 
is that paleontology is a part of zoology 
or the study of animal life; that zoology 
is a part of biology ; and that biology is the 
common-sense, the rationale, the philosophy 
of living nature as a whole. 
The true modern spirit in which to study 
a fossil vertebrate is to imagine it as living, 
moving, walking, swimming or flying, be- 
getting its kind. The size of the brain, 
which is really ascertained by studying its 
cavity in the skull, has been the subject of 
special researches by Leuret, Marsh, Cope 
-and Bruce; the size and position of the 
organs of sight and smell are among the 
data of fossil psychology. Therefore we 
can study a fossil as thinking, that is, fear- 
ing its enemies, devising means of escape 
either by adhering to its friends in herds or 
by swift solitary flight. But such knowl- 
edge is not obtained from a few fragments; 
we need a very large part of the skeleton of 
an animal and information concerning its 
contemporaries before we can begin to draw 
such inferences, and one of the greatest ad- 
vances of recent work consists in the fact 
that we have secured complete skeletons in 
the place of fragmentary parts. 
If the remains of an animal are found 
with many others of its kind as in the case 
of five skeletons of Merycochoerus recently, 
found by one of the American Museum ex- /\ 
peditions, you infer that it was gregarious; 
if always found isolated you infer that it 
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