NO. 2086. 



SOME MAMMALS 



OF THE PLEISTOCENE— HAY. 



563 



Fossil horse from Remagen. 



Basilar 

 length. 



Vertex 

 length. 



Frontal 

 width. 



Cephalic 

 index. 



Cranial 

 length. 



Cranio- 



cephalic 



index. 



Facial 

 length. 



Facio- 



cephalic 



index. 



For. mag. 

 to vomer. 



Vomer to 

 palate. 



528 



mm. 

 562 



mm. 

 212? 



40.1 



mm. 

 180 



34.1 



mm. 

 388 



73.5 



mm. 

 139 



mm. 

 112 



A comparison of the estimates printed here with those of the table 

 of large domestic horses shows that the Remagen horse agrees in all 

 essential respects with the former. This was the conclusion reached 

 by Nehring himself. 



It is believed by many that the late Pleistocene ancestors of Prze- 

 valsky's horse took part as one of the constituents of Equus caballus. 

 A comparison of the table devoted to this species with that dealing 

 with the domestic horses shows that Przevalsky's horse is interme- 

 date in size between the large ones and the small ones; that the ce- 

 phalic index is intermediate, but nearer the large horses; that the 

 cranio-cephalic index is nearer that of the small horses ; and that the 

 facio-cephalic index has an average above both groups. There ap- 

 pears to be no reason whatever for supposing that E. przevalskii had 

 anything to do with either of them. 



One might suppose, however, that E. przevalskii formed an im- 

 portant element in horses of intermediate size, Ewart, for various 

 reasons, believes that this species, or something like it, enters into 

 composition of all the long-faced horses; but the tables here presented 

 show that the large, heavy, apparently long-faced horses have really 

 the facio-cephalic index lower than do the smaller and broad-faced 

 horses. Duerst concludes that the Przevalsky horse stands in close 

 relationship with certain European Pleistocene horses. Salensky 

 thought it might possibly have an affinity to the pony ; and Noack, as 

 noted by Ewart, held this view strongly. To these views there are 

 some objections. 



1. The presence of E. przevalskii in Europe has not been proved. 

 There may have been another species in Europe in the Pleistocene 

 which resembled it, but which became extinct, 



2. The inclusion of the Przevalsky horse in Equus caballus would 

 compel the admission that in Europe there were, during the late 

 Pleistocene, three distinct species of horses which could be made to 

 breed freely together. It is difficult to believe that two species could 

 be made to interbreed; it is improbable that three could be induced 

 to do so. 



3. In case Przevalsky's horse had entered to any considerable ex- 

 tent into the formation of our domestic horses, we might naturally 

 expect that there would be displayed more conspicuously in some of 

 the domestic races those external characters which Salensky has 



