Chap. I. THEIR PARENTAGE. 29 



tan-coloured stripe over the eyes, feet, and chaps; and what is more 

 singular, he figures the Alco, or native domestic dog of Mexico, as black 

 and white, with narrow tan-coloured rings round the eyes ; at the Exhi- 

 bition of dogs in London, May, 1863, a so-called forest dog from North- 

 West Mexico was shown, which had pale tan-coloured spots over the eyes. 

 The occurrence of these tan-coloured spots in dogs of such extremely 

 different breeds, living in various parts of the world, makes the fact highly 

 remarkable. 



We shall hereafter see, especially in the chapter on Pigeons, that 

 coloured marks are strongly inherited, and that they often aid us in dis- 

 covering the primitive forms of our domestic races. Hence, if any wild 

 canine species had distinctly exhibited the tan-coloured spots over the eyes, 

 it might have been argued that this was the parent-form of nearly all our 

 domestic races. But after looking at many coloured plates, and through 

 the whole collection of skins in the British Museum, I can find no species 

 thus marked. It is no doubt possible that some extinct species was 

 thus coloured. On the other hand, in looking at the various species, 

 there seems to be a tolerably plain correlation between tan-coloured legs 

 and face ; and less frequently between black legs and a black face ; and 

 this general rule of colouring explains to a certain extent the above-given 

 cases of correlation between the eye-spots and the colour of the feet. 

 Moreover, some jackals and foxes have a trace of a white ring round their 

 eyes, as in 0. mesomelas, 0. aureus, and (judging from Colonel Ham. Smith's 

 drawing) in C. alopex and C. thaleb. Other species have a trace of a black 

 line over the corners of the eyes, as in C. variegatus, cinereo-variegatus, and 

 fulvus, and the wild Dingo. Hence I am inclined to conclude that a 

 tendency for tan-coloured spots to appear over the eyes in the various 

 breeds of dogs, is analogous to the case observed by Desmarest, namely, 

 that when any white appears on a dog the tip of the tail is always white' 

 " de maniere a rappeler la tache terminale de meme couleur, qui caracterise 

 la plupart des Canides sauvages." 40 



It has been objected that our domestic dogs cannot be 

 descended from wolves or jackals, because their periods of ges- 

 tation are different. The supposed difference rests on statements 

 made by Buffon, Gilibert, Bechstein, and others; but these 

 are now known to be erroneous; and the period is found to 

 agree in the wolf, jackal, and dog, as closely as could be ex- 

 pected, for it is often in some degree variable. 41 Tessier, who 



« Q U0ted b p r0 f. G e rva i s , * Hist. that the gestation of a mongrel from 



'fSlnte ! 11 '?; « , - lf -d dog C Phil. Transact 1789, p. 



_ J. Hunter shows that the long 160) apparently was sixty-three days 



period of seventy-three days given by for she received'the dog more than once 



Buffon is easily explained by the bitch The period of a mongrel dog and jackal 



having received the dog many times was fifty-nine days. Fred. Cuvier found 



S^^ifSX*? 7^ tlle P-odofgesLionofthewolftobe 

 Transact., 1/87, p. 353). Hunter found (< Diet. Class. d'Hist. Nat.,' torn. iv. p. 



