GERMINAL SELECTION. 31 



vacillations in the size of the organ in question have 

 possessed selective value. On the contrary, we see 

 such retrogressions affected apparently in the shape of 

 a continuous evolutionary process determined by in- 

 ternal causes, in the case of which there can be no 

 question whatever of selection of persons or of a sur- 

 vival of the fittest, that is, of individuals with the 

 smallest rudiments. 



It is this consideration principally that has won so 

 many adherents for the Lamarckian principle in re- 

 cent times, particularly among the paleontologists. 

 They see the outer toes of hoofed animals constantly 

 and steadily degenerating through long successions of 

 generations and species, concurrently with the re-en- 

 forcement of one or two middle toes, which are pre- 

 ferred or are afterwards used exclusively for step- 

 ping, and they believe correctly enough that these 

 results should not be ascribed to the effects of per- 

 sonal selection alone. They demand a principle which 

 shall effect the degeneration by internal forces, and be- 

 lieve that they have found it in functional adaptation.* 



1 On the same day on which the present address was de- 

 livered at the International Congress of Zoologists in Leyden, 

 and on the same occasion, Dr. W. B. Scott, Professor of 

 Geology in Princeton College, New Jersey, read a very inter- 

 esting paper on the tertiary mammalian fauna of North Amer- 

 ica, in which, without a knowledge of my paper, he took his 

 stand precisely on this argument and arrived at the opinion 

 that it could not possibly be the ordinary individual varia- 

 tions which accomplished phyletic evolution, but that it was 

 necessary to assume in addition phyletic variations. I believe 

 our views are not as widely remote as might be supposed. 

 Of course, I see no reason for assuming two kinds of hered- 

 itary variations, different in origin. Still it is likely that only 

 a relatively small portion of the numberless individual varia- 

 tions lie on the path of phyletic advancement and so under 



