54 A NEW THEORY OF EVOLUTION. 



embryo of the mammal of to-day has been 

 specifically affected by environment, or by 

 the varying conditions of life to which the 

 progenitors have been subjected. 



That in the growth of the embryo of an 

 existing mammal we witness the processes 

 of Specific Variation that evolved the first 

 of its type. 



Type is therefore specifically immutable. 



These conclusions are exemplified in the 

 life-history of the whale; for, notwithstand- 

 ing the numberless generations of whales 

 procreated since their first appearance, and 

 the vast differences in the conditions of life 

 of the whale in water and of its antecessor 

 on land, the embryo of the whale still pre- 

 sents traces, and the mature animal frag- 

 ments of organs, that were fully developed 

 in its four-footed antecessor. 



We have traced the Specific Variation of 

 mammals backwards to the womb of the first 

 progenitor of a race ; but we know no more 

 of the cause of the variation, or of how it 

 was effected, than we do of the origin of life, 

 of which indeed Specific Variation was but 

 a new and higher manifestation presumably 

 by the same Cause. But having regard to 

 Nature's parsimony in the use of means, we 

 may imagine that a new type was evolved by 



