Plistocene Bison 63 



connected by way of Bering Strait, so tliat it would be natural to expect 

 to find identical animals on both sides of the line of these straits. And, 

 as a matter of fact, no one has disputed that the remains of the horse, 

 mammoth, and musk-ox found in the northern parts of the two hemi- 

 spheres are specifically identical. 



Possibly there may be sub-specific differences, but it appears to me 

 necessary to accept the conclusion that the Plistocene bison was a circum- 

 polar species, whose somewhat degenerate descendants developed on the 

 two sides of the Pacific respectively into the living European and American 

 bisons. The earliest known bison in the Old World is the species of 

 which the remains occur in the upper Pliocene deposits of Northern 

 India ; and as the group may certainly be regarded as of Old World origin, 

 it seems very doubttul it it entered America before the Plistocene epoch. 

 Hence I teel considerable doubt in admitting that certain remains from 



o 



America are, as is stated to be the case, really of older Pliocene age. 

 The names ot these are purposely omitted here, but allusion is made later 

 on to certain other remains from various parts of America which may 

 indicate distinct species, and are in any case of considerable interest from 

 a distributional point of view. In the eastern hemisphere this bison 

 doubtless eventually passed into the living European form, and in the 

 western into the woodland race of the existing American representative 

 of the group. 



The following are tlie dimensions of the horn-cores of five specimens 

 in the British Museum. Several of these in their present condition show 

 some or all tlieir dimensions exceeding those recorded in either of the 

 existing forms. And it must be remembered that to make a true com- 

 parison, the horn-cores of the latter should alone be measured ; in other 

 words, the horny external sheaths should be added to the measurements 

 of the fossils, which would give a considerable increase : — 



