32 DOGS. Chap. I 



known, mutually fertile together. But, as Broca has well 

 remarked, 45 the fertility of successive generations of mongrel 

 dogs has never been scrutinised with that care which is 

 thought indispensable when species are crossed. The few 

 facts leading to the conclusion that the sexual feelings and 

 reproductive powers differ in the several races of the dog 

 when crossed are (passing over mere size as rendering pro- 

 pagation difficult) as follows : the Mexican Alco 46 apparently 

 dislikes dogs of other kinds, but this perhaps is not strictly a 

 sexual feeling ; the hairless endemic dog of Paraguay, ac- 

 cording to Eengger, mixes less with the European races than 

 these do with each other ; the Spitz dog in Germany is said 

 to receive the fox more readily than do other breeds ; and Dr. 

 Hodgkin states that a female Dingo in England attracted the 

 male wild foxes. If these latter statements can be trusted, 

 they prove some degree of sexual difference in the breeds of 

 the dog. But the fact remains that our domestic dogs, 

 differing so widely as they do in external structure, are far 

 more fertile together than we have reason to believe their 

 supposed wild parents would have been, Pallas assumes 47 

 that a long course of domestication eliminates that sterility 

 which the parent-species would have exhibited if only lately 

 captured ; no distinct facts are recorded in support of this 

 hypothesis ; but the evidence seems to me so strong (indepen- 

 dently of the evidence derived from other domesticated 

 animals) in favour of our domestic dogs having descended from 

 several wild stocks, that I am inclined to admit the truth of 

 this hypothesis. 



There is another and closely allied difficulty consequent on 

 the doctrine of the descent of our domestic dogs from several 

 wild species, namely, that they do not seem to be perfectly 

 fertile with their supposed parents. But the experiment has 

 not been quite fairly tried ; the Hungarian dog, for instance, 



45 'Journal de la Fhysiologie,' torn. 'Naturgesch. Deutschlands,' 1801, 

 ii. p. 385. B. i. s. 638. With respect to Dr. 



46 See Mr. R. Hill's excellent ae- Hodgkin's statement made before 

 count of this breed in Gosse's Brit. Assoc, see 'The Zoologist,' vol. 

 'Jamaica,' p. 338; Rengger's ' Sauge- iv., for 1845-46, p. 1097. 



thiere von Paraguay,' s. 153. With 47 'Acta Acad. St. Petersburgh, 



respect to Spitz dogs, see Bechstein's 1780, part ii. pp. 84, 100. 



