3oo OWEN'S POSITION IN 



far as the typical forms of the several groups 

 to which they belong are soon assumed, and, 

 thereafter, each pursues the special line of 

 modification characteristic of its group, ' unity of 

 organisation ' soon ceases to be strictly predicable. 

 Thus Geoffroy was right about the fundamental 

 unity of animal organisation, and Cuvier was right 

 about the existence of different types irreducible to 

 one another ; while each erred in thinking his own 

 views incompatible with those of his opponent. 



In the course of the discussions about the 

 corresponding, or answering, parts in different 

 organisms, or in the same organisms, and about 

 questions of classification, a very useful termin- 

 ology had been invented. When the systematists 

 attempted to construct a scientific classification, 

 they found themselves obliged to discriminate 

 between different kinds of resemblances. Take, 

 for example, the question whether a whale is a 

 fish or not, which, I observe, is not yet quite settled 

 for some people. As a whale is not a little like a 

 fish outside, and lives permanently in the sea, 

 after the manner of a fish, why should it not be 

 classed with the fishes ? The answer, of course, 

 is that the moment one compares a whale with any 

 one of the thousands of ordinary fishes, the two 

 are seen to differ in almost every particular of 

 structure ; and, moreover, in all these points in 

 which the whale differs from the fish, it agrees 



