238 
tinually the subject of Cope’s researches, 
and he attempted to trace the passage from 
those of the most ancient periods to those 
of later ones. 
VII. 
Cope was not satisfied with the study of 
morphological details or simple taxonomy. 
He aspired to know how animals came into 
existence ; why they varied as they did, and 
what laws determined their being. His was 
an eminently philosophical mind, but at 
the same time with a decided tendency to 
metaphysical speculation. In one of his 
earliest papers he manifested this tendency 
and it persisted through life. It is with 
much hesitation that I venture to give an 
exposition of his most salient views, for I 
must confess I do not altogether like his 
philosophy and am able to subscribe to it 
only in part. I cannot but wish that one 
of his numerous disciples could have been 
chosen for this task. But I cannot pass it 
by, for it is the most characteristic feature 
of Cope’s work and the one he most 
esteemed. 
Cope began his public scientific career, 
it will be remembered, in the same year in 
which Darwin’s long studies had fructified 
into his ‘ Origin of Species.’ 
As was quite natural with his keen in- 
stinets, Cope early adopted the doctrine of 
transmutation of species and recognized the 
truth that all the animals of the present 
epoch are descendants from those of past 
times with modifications which separate 
them as species, and eventually as repre- 
sentatives of genera, of families and orders 
differing from the earlier ones as we retrace 
the steps of Time farther and farther back. 
He was not, however, satisfied with Dar- 
win’s theory, and denied that natural selec- 
tion was a sufficient factor for differentia- 
tion. He would not admit that animals were 
passive subjects and that the slight varia- 
tions which were manifest in the progeny of 
species were sufficient to enable nature to 
SCIENCE. 
[N.S. Vou. VI. No. 137. 
select from and to fit for future conditions. 
He contended that the volition and en- 
deavors of an animal had much to do with 
future progeny as well as its own brief life. 
In short, he claimed that characters ac- 
quired by animals through their own efforts 
or forced on them by various external 
agencies or accidents might be transmitted 
to their offspring. He further, first in a 
in a chapter in his ‘Synopsis of the Cypri- 
nide of Pennsylvania’ outlined, and later, 
in ‘The Origin of Genera,’ hé elaborated, a 
peculiar theory characterized mainly by 
what he called (with Professor Hyatt) 
‘the law of acceleration and retardation’ in 
development. Darwin complained that he 
could never understand this law, and Cope 
complained that Darwin had not stated his 
views correctly in an attempted abstract. 
I therefore give Cope’s views, restated in his 
own language, summarizing them years 
afterwards. ‘The following doctrines,” he 
he says, ‘‘ were taught :” 
‘*Pirst, that the development of new characters has 
been accomplished by an acceleration or retardation in 
the growth of the parts changed. This was demon- 
strated by reference to a class of facts, some of which 
were new, which gave ground for the establishment 
of the new doctrine. 
Second, that of exact parallelism between the adult 
of one individual or set of individuals and a transi- 
tional stage of one or more other individuals. This 
doctrine is distinct from that of inexact parallelism 
which had already been stated by von Baer. And 
that this law expresses the origin of genera and higher 
groups, because, 
Third, they can only be distinguished by single 
characters when all their representatives come to be 
known. 
Fourth, that genera and various other groups have 
descended, not from a single generalized genus, etc., 
of the same group, but from corresponding genera of 
one or more other groups. This was called the doc- 
trine of homologous groups. 
Fifth, the doctrine that these homologous groups 
belong to different geological periods, and, 
Sixth, to different geographical areas, which, there- 
fore, in some instances, are, 
Seventh, related to each other in a successional way 
like the epochs of geological time. 
WLAN. « /3 J / /) fa DY 
