166 A Review of the Modern Doctrine of Evolution. [ March, 
The same paper is adapted to the AMERICAN NATURALIST for 
December, 1879, pp. 7718-7, with eight cuts. 
Pages 798a-%, of AMERICAN NATURALIST for December, give in 
brief some of the more important results of Mr. Cope’s recent 
trip to the Pacific coast, describing among other things the 
remarkable new fossil cats, Archelurus debilis and Hoplophoneus 
platycopis. 
Mr. Cope’s Palzontological Bulletin, No. 31, being a “Second 
Contribution to a Knowledge of the Miocene Fauna of Oregon,” 
“read before the American Philosophical Society, December 5, 
1879,” contains descriptions of the following new fossil mammals: 
Hesperomys nematodon, Sciurus vortmani, Canis lemur, Chenohyus 
(g. n.) decedens, Thinohyus trichenus, Pale@ocherus subequns, Colo- 
reodon (g. n.) ferox, C. macrocephalus. The date of printing is 
given as December 24, 1879. 
guenan ©. 
A REVIEW OF THE MODERN DOCTRINE OF 
EVOLUTION. 
BY E. D: COPE. 
HE doctrine of evolution of organic types is sometimes appro- 
priately called the doctrine of derivation, and its supporters, 
derivatists. This is because it teaches the derivaticn of species, 
genera and other divisions, from pre-existent ones, by a process 
of modification in ordinary descent by reproduction. The oppo- 
site or creativist doctrine teaches that these forms were created as 
we see them to-day, or nearly so; and that the natural divisions 
and species of organic beings have-never been capable of change, 
the one into the other. 
I. The Evidence for Evolution. 
The reasons which induce me to accept the derivatist doctrine, 
and to reject the creational, fall under the two heads of pro- 
babilities and conclusive evidence. The probabilities are cumula- 
tive in their pointings, and form part of a total body of evidence 
which is, to my mind, conclusive. The reasons why derivation 
is probable are the successional relation of increment or decre- — 
ment of structure, observed i in: 
1 Abstract a a lecture delivered before the California Academy of Sciences, Oct. © 
27, 1879. ae 
