EVOLUTION AND ITS CONSEQUENCES. 9 



animals, and less to the whole animal. When we reach species as 

 far removed as man and a shark, which are separated by the ex- 

 tent of the series of vertebrated animals, we can only say that the 

 infant man is identical in its numerous origins of the arteries from 

 the heart, and in the cartilaginous skeletal tissue, with the class of 

 sharks, and in but few other respects. But the imjoortauce of this 

 consideration must be seen from the fact that it is 07i single char- 

 acters of this hind that the divisions of the zoologist depend. 

 Hence we can say truly that one order is identical with an incom- 

 plete stage of another order, though the species of the one may 

 never at the present time bear the same relation in their entirety 

 to the species of the other. Still more frequently can we say that 

 such a genus is the same in character as a stage passed by the next 

 higher genus ; but when we can say this of species, then their dis- 

 tinction is almost gone. It will then depend on the opinion of 

 the naturalist as to whether the repressed characters are perma- 

 nent or not. Parallelism is then reduced to this definition : that 

 each separate character of every kind, which we find in a species, 

 represents a more or less complete stage of the fullest growth of 

 which the character appears to be capable. In proportion as those 

 characters in one species are contrasted with those of another by 

 reason of their number, by so much must we confine our compari- 

 son to the characters alone, and the divisions they represent ; but 

 when the contrast is reduced by reason of the fewness of differing 

 characters, so much the more truly can we say that the one species 

 is really a suppressed or incomplete form of the other. The denial 

 of this principle by the authorities cited has been in consequence 

 of this relation having been assigned to orders and classes, when 

 the statement should have been confined to single characters ; and 

 divisions characterized by them. There seems, however, to have 

 been a want of exercise of the classifying quality or power of *^ ab- 

 straction " of the mind on the part of the objectors. This faculty 

 seems to be by no means so common as one would expect, judging 

 from the systematic ideas of many. 



To explain by a few examples selected at random : First, of 

 species characters, I may cite the fact that all deer are spotted 

 when young, and that some of the species of eastern and southern 

 Asia retain the spotted coloration throughout life. All salaman- 

 ders are uniform, often olive during a larval stage ; some species, 

 and some individuals of other species, retain the color in maturity. 

 To take a genus character : all the deer in the second year develop 



