30 DOGS. Chap. I. 



has closely attended to this subject, allows a difference of four 

 days in the gestation of the dog. The Kev. W. D. Fox has 

 given me three carefully recorded cases of retrievers, in which 

 the bitch was put only once to the dog; and not counting 

 this day, but counting that of parturition, the periods Vere 

 fifty-nine, sixty-two, and sixty-seven days. The average period 

 is sixty-three days ; but Bellingeri states that this holds good 

 only with large dogs ; and that for small races it is from sixty 

 to sixty-three days ; Mr. Eyton of Eyton, who has had much 

 experience with dogs, also informs me that the time is apt to 

 be longer wdth large than with small dogs. 



F. Cuvier has objected that the jackal would not have been 

 domesticated on account of its offensive smell ; but savages are 

 not sensitive in this respect. The degree of odour, also, differs 

 in the different kinds of jackal ; 42 and Colonel H. Smith makes 

 a sectional division of the group with one character dependent 

 on not being offensive. On the other hand, dogs — for instance, 

 rough and smooth terriers — differ much in this respect; and 

 M. Godron states that the hairless so-called Turkish dog is 

 more odoriferous than other dogs. Isidore Geoffroy 43 gave to 

 a dog the same odour as that from a jackal by feeding it on raw 

 flesh. 



The belief that our dogs are descended from wolves, jackals, 

 South American Canidse, and other species, suggests a far more 

 important difficulty. These animals in their undomesticated 

 state, judging from a widely-spread analogy, would have been in 

 some degree sterile if intercrossed ; and such sterility will be 

 admitted as almost certain by all those who believe that the 

 lessened fertility of crossed forms is an infallible criterion of 

 specific distinctness. Anyhow these animals keep distinct in 

 the countries which they inhabit in common. On the other 

 hand, all domestic dogs, which are here supposed to be descended 



8) two months and a few days, which the dog. 



agrees with the dog. Isid. G.St. Hilaire, 42 See Isid. Geoffroy St. Hilaire, 



who has discussed the whole subject, 'Hist. Nat. Ge'n.,' torn. iii. p. 312, on 



and from whom I quote Bellingeri, states the odour of jackals. Col. Ham. Smith, 



(« Hist. Nat. Gen.,' torn. iii. p. 112) that in ' Nat. Hist. Lib.,' vol. x. p. 289. 



in the Jardin des Plantes the period of 43 Quoted by Quatrefages in ' Bull- 



the jackal has been found to be from Soc. d'Acclimat.,' May 11th, 1863. 

 sixty to sixty-three days, exactly as with 



