32 DOMESTICATED ANIMALS 



ures which are the most interesting part of our dogs, the 

 experiments have served to show the amazing physical 

 plasticity of this species under the conditions of long domes- 

 tication. The range in 'size between a tiny spaniel, such as 

 those which are bred in Chihuahua, in northern Mexico, and 

 the great Danes or mastiffs of northern Europe, is, perhaps, 

 the greatest which has ever been attained in any mammal. 

 In some cases the larger individuals belonging to the mastiff 

 breed probably weigh nearly thirty times as much as their 

 smaller kinsmen. Great as are these variations, they are 

 only in form and bulk. They involve none of those curi- 

 ous changes in the number of bones of the skeleton which 

 we may trace among the domesticated pigeons. We there- 

 fore turn from these results of breeders' fancy to consider 

 certain of the mental qualities of dogs which have not come 

 in our way in our review of the history of its relations to 

 man. 



First of all, we may note the fact that the friendly rela- 

 tions which dogs have become accustomed to form with men 

 vary exceedingly in their range and activity. Perhaps in no 

 other regard does the dog exhibit such distinctly human char- 

 acteristics as in the way in which he meets the individuals of 

 the mastering species. The gamut of their social relations 

 with men is almost exactly parallel with our own. With from 

 one to a dozen persons a dog may maintain an attitude of 

 almost equally complete sympathy and mutual understanding. 

 He may be on terms of acquaintanceship in varied degrees 

 of familiarity with a few score others with whom he comes in 

 frequent contact. Toward the rest of mankind he maintains 

 a position of more or less complete distrust, which with 

 experience may attain the indifference which men commonly 



