317 
1872.] [Cope. 
As the essay read before this Society under the above title, adduces no 
facts for or against the theory of Evolution not already known, the writer 
does not propose to criticise it as a whole. His object is to correct some 
statements of supposed fact, which are germane to the argument of the 
essay, in which its author has been led astray by the statements of 
others, or want of familiarity with the subject. 
The erroneous statements are the following : 
Ist. That the gradations of variational and specific form seen among 
domesticated animals are peculiar to them, not being found among ani- 
mals in the wild state ; and are therefore due exclusively to the influence 
of human interference. 
2d. That fertile hybrids do not exist in the wild state, and that their 
existence between domesticated varieties is therefore evidence of their 
‘common origin. 
3d. That transitions from species to species, as to form and other essen- 
tials, occur neither in the present period nor in the succession of geologic 
strata. 
4th. That the examples of intermediate forms, or supposed transitional 
structures, on which the evolutionists rely, are abnormal or monstrous, 
or otherwise insufficient for the use made of them. 
These are four very natural popular fallacies, and the present seems to 
be a suitable opportunity for exposing them. 
First. That graded varieties and unstable specific forms do not exist 
outside of domestication, and are due to its influence, ete. To find an 
unqualified contradiction to this statement, it is only necessary to refer to 
the diagnostic tables and keys of the best and most honest zodlogists and 
botanists. It is true that these diagnoses are dry reading to the non-pro- 
fessional, yet they embrace nearly all that is of value in this part of bio- 
logical science, and must be mastered in some department, before the 
student is in possession of the means of forming an opinion. The neglect 
to do this explains why it is that, after all that has been written and said 
about protean species, etc., the subject should be so little understood. 
The fact is thus: That in every family or larger group of animals and 
plants, there exists one or more genera in which the species present an 
ageregation of specific intensity of form; that is, that species become 
more and more closely related, and, finally, varieties of single species have 
to be admitted for the sake of obtaining a systematic diagnosis, which will 
apply to all the individuals. These varieties are frequently as well marked 
as the nearly related species, so far as amount of difference is concerned, 
the distinction between the two cases being that in the varieties there is 
a gradation from one to the other; in the species, none. Nevertheless, 
between some of the varieties, transitions may be of rare occurrence, and 
in the case of the ‘‘species,’’? an intermediate individual or two may oc- 
casionally be found. Thus it is that differences of the varietal and of the 
specific kinds are distinguished by degree only, and not in kind, and are 
therefore the results of the operation of uniform laws. Yet, according 
