192 
27th report, bureau of animal industry. 
LEPTOBOVINE GROUP SUBGENUS LEPTOBOS. 
This group consists of extinct species only, and the different mem- 
bers will be treated later. 
BISONTINE GROUP SUBGENUS BISON. 
The important members of this group are the European bison, the 
American bison, and the yak. They may at different times have been 
crossed with Bos primigenius and Bos longifrons^ as the Ameri- 
can bison is being used at the present time in the United States with 
some of the best beef breeds with the expectation of producing a bet- 
ter breed of beef cattle than any now known. The resulting cross is 
commonly spoken of as a " cattalo." 
Bos grunniens, or the yak, ranges over nearly the entire central 
part of Asia. The domesticated yak, though somewhat smaller in 
size, is probably derived directly from the wild form. Kohler, 
however, thinks the domesticated form is a cross between the wild 
yak bull and a domesticated cow of the Taurine group. Kegel 
(1884) also is of the opinion that there is yak blood in the long- 
haired cattle of the upper Oxus. 
BUBALINE GROUP SUBGENUS BUBALUS. 
The buffalo is a domesticated animal of considerable importance 
in southeastern Europe and southern and eastern Asia. It is used 
as a draft animal and for beef production, and in some sections is 
the principal dairy animal. 
The domesticated buffalo was known in Europe previous to Roman 
times. It was first introduced as a domesticated animal into Italy 
at the end of the sixth century. Before that time it was common 
in the region of the Danube and had probably come from Asia. 
There was, however, a Pleistocene form. Bos antiquus^ the Algerian 
buffalo, which roamed from Algeria to South Africa, and it is pos- 
sible that the different species of domesticated -buffaloes have origi- 
nated from several w^ild species of this group. 
EXTINCT SPECIES IN RELATION TO ANCESTRY OF DOMESTICATED 
CATTLE. 
In considering the extinct species which may possibly be ancestors 
of domesticated European varieties of cattle one can not at present 
go back further in geological history than the horizons in the 
Pliocene epoch. 
