300 
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 
