218 



THE AMERICAN NATURALIST 



[Vol. XLI 



ance of Darwin's Origin of Species, first as an advocate of the 

 theory of Natural Selection, but shortly as its opponent. Through 

 twenty years of controversy he insisted upon the inadequacy of 

 Natural Selection, and as the prime factor in the diversification 

 of species sought to substitute Spatial Separation and to estab- 

 lish his own Law of IVIigration and Colony-formation. He sup- 

 posed a new species to arise by the migration or escape of a single 

 individual or of a pair from the domain of the old species into 

 new territory, where in geographic isolation and freedom from 

 the influence of the old stock a new race might be founded. The 

 divergence of the race from the old type he supposed to result 

 (Wagner, '89, pp. 286-295, 401) (1) from the individual peculiari- 

 ties of the parental pair or individual, which peculiarities in the 

 absence of the normalizing influence of interbreeding with the 

 whole body of the old stock would necessarily become accen- 

 tuated; and, (2) from the new environment. His theoretical 

 view^s, which throughout are questionable, are of less consequence 

 than the facts which he adduced in their support; the facts indeed 

 upon which he first formed these views. Wagner himself was a 

 traveler, observer, and collector in several i)arts of the wc)rld and 

 continually recurs in his writing to his ex])erience ni the field with 

 regard to endemic, narrowly r( 



tant local varieties 



elming numbers. 



ill classes of animals and to some 

 extent also from plants. He represents specific distribution as 

 having a strictly mosaic or chain-like character. Everywhere we 

 find vicarious species and local races in separate habitats. Ihe 

 facts are presented at great length and with careful detad, and 

 seem to form a consistent body of knowledge, which impresses one 

 as being pregnant with a rational principle of wide import. 



Mr. C. H. Merriam about a year ago addressed the zoological 

 section of the American Association for the Advancement of 

 Science on the topic, "Is Muta 

 the higher vertebr 



(Merri 



arguments 



and conclusions ] 



long, to my mind, too largely in the eonjeel uval 

 while this author's grasp upon the real character o t e iu> 

 work and upon his theory seems comparatively feeble, the da 



