CA>-IS FAMILLA.EIS. 167 



Dr. "W. Lockbart wrote to Dr. Grav as follows : — " The Put^-nosed 

 Dog, the skull of which I sent you, probably originated in Pekin and 

 North China, and was taken thence to Japan, whence it was brought to 



Europe ; and thus this breed is called Japanese There are two 



kinds of Pug in China: — one a small black-and-white. Ions-lettered, 

 pug-nosed, prominent-eyed dog ; the other long-backed, short-legged, 

 long-haired, tawny-coloured, with pug-nose and prominent eyes. 

 Sometimes in these dogs the eyes are so prominent that I have known 

 a dog have one of his eyes snapped off by another dog at play. The 

 preference for vegetable food is a fact ; but I think it is a result of 

 education, as most of them will take animal food : this is usuallv kept 

 from them so that their growth and organization may be kept down. 

 The sleeve-dog is a degenerated long-legged variety of pug rigidly kept 

 on low diet, and never allowed to run about on the ground ; they are 

 kept very much on the top of a kang or stove bed-place, and not allowed 

 to run about on the ground, as it is supposed . . . they will derive 

 strength from the ground and be able to grow large. Their food is 

 much restricted, and consists chiefly of boiled rice. They are very 

 subject to comeitis and ulceration of the cornea from deficient nutrition." 



The various breeds of Dogs being so extraordinarily diverse, a question 

 which forces itself on our minds is, " What has been the origin of an 

 animal thus exceptionally polymorphic r " The problem may be 

 exhaustively expressed as follows : — 



Did all domestic races spring, 



(1) from one species of true dog still existing? 



(2) from more than one species of true dog still existing ? 



(3) from one species of true dog now extinct ? 



(4) from more than one species of true dog now extinct ? 



(5) from one species, not a true dog, now existing ? 



(6) from several species, not true dogs, now existing ? 



(7) from one species, not a true dog, now extinct ? 

 (S) from several species, not true dogs, now extinct ? 



At first it might seem reasonable to suppose that animals so diverse 

 as are the Spaniel, the Deerhound, and the Pug-dog have descended 

 from distinct species, each of which possessed the characteristics of 



