216 MERISTIC VARIATION. [part i. 



of the Esquimaux are rather with American tribes than with 

 Europeans. If this were established, it would be not unlikely 

 that the Esquimaux dogs might be descended from dogs domesti- 

 cated in America before the coming of Europeans, and so far belong 

 rather with the Inca dogs than with ours 1 . 



*244. Inca Dogs. The domestic dogs from the Inca interments, be- 

 longing to a period before the coming of the Spaniards, have been 

 investigated by Nehrixg. Of nine skulls not one had the full number 

 of teeth and there was no case of supernumerary teeth. Sometimes 

 the anterior premolar was absent, sometimes a posterior molar, and in 

 some cases both. The formulae were as follows: 



4—4 2 — 2 n 



P 4IZ3 ' m 2=3 case ' 



4—4 2 — 2 . 



P 3=3 ' m 3=2 T CaSe - 



4—4 2 — 2 _ 



p g— - , m ^— - 3 cases. 



4 — 4 2 — 1 . 



p 3=3 ' m 2=2 l CaSe - 



4_3 2 — 2 , 



^1=4' m 2=2 1 case - 



3—3 2 — 2 n 



2> 3 _^3 1 m JZL3 2 cases - 



The clogs were all of moderate size, and none shewed any defects 

 in the form of teeth, which were all strong and sound. Nehrixg, A., 

 Kosmos, 1884, xv. p. 94. 



Variation (? Homceotic) in form of third Premolar. 



*245. Dog : large breed. In the upper jaw on both sides the third 

 premolar, instead of having only two roots, has a third internal root, 

 thus somewhat resembling the carnassial. The crown of the tooth 

 very slightly changed. This is not a case of persistent milk-tooth, which 

 though a three-rooted tooth, is very different. C. S. M., 558. 



III. Variation in Molars. 



Supernumerary molars are not rare in Canidse. In all cases 

 seen by me these teeth are single-rooted, round-crowned, rather 

 tubercular teeth, placed behind w 2 or m? as the case may be. 

 Hensel 1 has observed that if m* occurs, then m? which is normally 

 single-rooted, not infrequently has a double root, though the same 

 variation may occur when there is no m 4 present. Conversely, 

 when m? is absent, not a rare variation, then m? is often of a 



1 Bartlett, arguing chiefly from habits, considers the Esquimaux dogs to be 

 domesticated wolves, and says that they often breed with the wolf. P. Z. S., 

 1890, p. 47. 



- Hensel, Morph. Jahrb., 1879, v. p. 539. 



