52 A NEW THEORY OF EVOLUTION. 



But presently the specific life-force of the 

 successor seems to prevail, that of the ante- 

 cessor is wholly superseded, and the foetus 

 is completed in the new type. The Green- 

 land whale, for example, has no teeth, and 

 yet its embryo at an early stage develops 

 incipient teeth that afterwards disappear, and 

 are replaced by whalebone. (See page 49.) 



These facts seem to disclose two anomalies 

 two forces at work in the development 

 of an embryo, and at one stage apparently 

 in conflict ; and again, the toothless whale 

 begets an embryo that, contrary to the law 

 of heredity as generally understood, develops 

 incipient teeth, and is in this respect unlike 

 its progenitors. 



How are these seeming anomalies to be 

 explained ? 



The apparent anomaly in the embryo of 

 the whale arises from imperfect apprehension 

 of the operation of heredity. 



There are three distinct phases in the 

 existence of a mammal the germ-cell, the 

 foetus, and the animal. Now, the law of 

 heredity prescribes that a mature mammal 

 shall reproduce its race, not by begetting a 

 miniature of itself, but a germ -plasm the 

 same as that from which itself was evolved ; 

 further, that this germ-plasm shall develop 



