HAIRLESS DUIKER AND DOG, AND BULLDOG-HEADED OALE. 2-io 



they were not very healthy. It would have been very 

 interesting to have ascertained if the formation of pigment in 

 the skin would have continued until the animals had become 

 completely black like the father. In this connection it should 

 be remembered that the father when a pup possessed a white 

 patch on the skin of the chest, as can be seen in the photo- 

 graph already referred to, and this patch became pigmented 

 as the animal grew up. 



William Bateson^ gives some interesting cases of the 

 hairless condition. Examples of naked mice (Mus mus- 

 culus) and shrew (So rex) are mentioned, and these were not 

 albinos, although there was no general pigmentation of the 

 skin. The author further states : "Naked horses have often 

 been exhibited. Such a horse caught in a semi-feral herd in 

 Queensland was described by I'egetmeier. The skin was 

 black and like india-rubber." 



With reference to hairless dogs. Belt- remarks that they 

 are to be met with in Central America, and "that they are of 

 a shiny dark colour, and are quite without hair, excepting a 

 little on the face and on the top of the tail. Both in Peru 

 and Mexico this variety was fouud by the Spanish con- 

 querors." The hairless dogs of China have apparently been 

 common from very early times. Although this race of hairless 

 dogs is common in Peru, yet it does not appear to have been 

 artificially preserved. Consequently it would seem that either 

 the race is more or less sterile when crossed with ordinary 

 hairy dogs, or the character is inherited with great intensity, 

 and is an example of a character like eye-colour which does 

 not readily mix in sexual reproduction. 



In this connection it is of much interest to note that some 

 of the offspring of the hairless fox-terrier above described 

 were hairless, while the remainder of the litter were com- 

 pletely normal. There is thus distinct evidence that the 

 " hairless " and hairy characters do not as a matter of fact 



' W. Bateson, ' Materials for the Study of Variation,' London, 1894, 

 p. 56. 



- T. Belt, ' Tlie Naturalist in Nicaragua,' London, 1874, p. 205. 



