436 bulletin: museum of comparative zoology. 



standing that domestication in case of most animals seems rather to 

 have a stultifying effect. A more diagnostic character is found in the 

 size of the teeth, Avhich e^•en in the largest breeds of dogs are con- 

 siderably smaller than in the wolves. A fact of probable significance 

 is that in wolves as in the less modified breeds of dogs, e. g., the 

 American Indian dogs, the free posterior border of the palate ends 

 about on a line passing transversely through the middle of the last 

 molar. In the large breeds of European dogs a transverse line at the 

 hinder margin of the palate usually falls considerably behind the last 

 molar, indicating probably that the teeth have retained more nearly 

 their original size relations than have the maxillar,^' and other bones. 

 A like condition is seen also in dogs in which the teeth are abnormally 

 reduced in size, due probably, as in case of the Chinese Chow Dog, to 

 a diet of soft foods as rice and fish through many generations. These 

 facts tend to indicate that the Dog and the large Wolf are really 

 distinct species, and that the wild progenitor of the Dog was a small 

 Wolf of a species distinct from the large wolves of circumboreal dis- 

 tribution. It is natural to look to Asia for this unknown ancestor, 

 and it would be valuable if the studies of Noack and Nehring as to 

 the small wolves of Tchili and Japan might be more fully confirmed. 

 Jentink (1S97) suggests the Wild Dog of Java as a representative of 

 the original stock whence the Domestic Dog sprang. 



Attention should here be called to the possible effect of domestica- 

 tion in reducing the size and proportions of the Wolf. Apparently 

 the only in\'estigator to compare the skulls of wolves born in captivity 

 with those of wild indi\iduals is Wolfgramm (1894), who states that 

 the skulls of the capti\-e-born wolves are smaller in all proportions, 

 broader and higher, with less developed muscle-crests. The snout 

 is so shortened that pm'^ is forced to assume a transverse position, 

 the lower premolars are imbricate, while in size the carnas.sial as well 

 as the other teeth are said to be slightl;\- reduced. Wolfgramm con- 

 cludes that this i? stifficient proof that the Dog is derived from the 

 European Wolf, and that its smaller size is a direct resiilt of its do- 

 mestication. The facts, however, do not warrant such a conclusion. 

 The reduced size of the skull and the crowding of the teeth in captive- 

 born wohes are probably a result of improper nutrition during growth 

 and lack of exercise under confinement, conditions wholly different 

 from the free life of a dog imder domestication. The crowding of 

 the premolars is quite as abnormal for a dog as for a wolf, and occurs 

 through failure of the maxillar,\- bones to attain their proper growth, 

 while the teeth themselves attain their size independently. 



