186 E VOL UT1 ON A ND DOGMA . 



each other that they would be regarded as belong- 

 ing not only to different species, but even to differ- 

 ent genera, did we not know that they are all de- 

 scended from the ordinary rock pigeon, Columbia 

 livia. For these birds, Huxley tells us, " not only 

 differ most singularly in size, color, and habit, but in 

 the form of the beak and the skull ; in the number 

 of tail feathers ; the absolute and relative size of the 

 feet ; in the presence or absence of the uropygial 

 gland ; in the number of the vertebrae in the back ; 

 in short, in precisely those characters in which the 

 genera and species of birds differ from one another." 

 And so it is with the different races of dogs. Whether 

 they are all originally descended from one or more 

 species is yet a moot question, although there is 

 reason to believe that most, if not all of them, are 

 descended from the wolf and the jackal. But be 

 this as it may, when we compare the divers races of 

 the domestic dog, when we observe how they differ 

 in the number of their teeth, toes and vertebrae, and 

 note the divergencies in the form and disposition of 

 other portions of the body, we see that they are so 

 unlike that if found in a state of nature they would 

 unhesitatingly be pronounced distinct species. Even 

 Cuvier was forced to admit, that the differences in 

 the forms of the skulls of certain canine races are so 

 great, as to justify one in assigning them to distinct 

 genera. 



What has been said of pigeons and dogs may 

 also, in great measure, be iterated in respect of sun- 

 dry races of fowls, rabbits, sheep and horses. Mor- 

 phologically their differences are so marked, that 



