818 EMBRYOLOGY AND CLASSIFICATION. 
tebrate type existed as a whole in the creative 
thought, and the first expression of it embraced 
potentially all the organic elements of that type, 
up to Man himself. To me the fact that the 
embryonic form of the highest Vertebrate recalls 
in its earlier stage the first representatives of its 
type in geological times and its lowest repre- 
sentatives at the present day, speaks only of an 
ideal relation, existing, not in the things them- 
selves, but in the mind that made them. It is 
true that the naturalist is sometimes startled at 
_ these transient resemblances of the young among 
the higher animals in one type to the adult con- 
dition of the lower animals in the same type; 
but it is also true that he finds each one of the 
primary divisions of the Animal Kingdom bound 
to its own norm of development, which is abso- 
lutely distinct from that of all the others; it is 
also true, that, while he perceives eorresponden- 
ces between the early phases of the higher animals 
and the mature state of the lower ones, he never 
sees any one of them diverge in the slightest 
degree from its own structural character, — never 
sees the lower rise by a shade beyond the level 
which is permanent for the group to which it 
belongs, never sees the higher ones stop short 
of their final aim, either in the mode or the 
extent of their transformation. I cannot repeat 
too emphatically, that there is not a single fact 
