4 
ANALYTIC STUDY OF FAUNAL CHANGES. 147 
the reason, from a biological standpoint, for the early dis- 
Se ae of the race. The reasons are several in number 
and it is not possible to say that any one is of much greater 
importance than the others. To quote again from Hornaday, 
“His ee of intellect was one of the most important fac- 
tors in his extermination.” This dullness of intellect mani- 
cdd itself chiefly in a stupid disregard for danger: the ani- 
mals instead of trying to escape often stood quietly watching 
the death dob ue id their companions who fell before the 
rifle of the still hun 
Such Amr titen en not be possible in a wild species 
that was not very perfectly adapted to its surroundings by 
sufficient size and str ength to render it immune to attacks 
by enemies. Large size, which was advantageous in enabling 
the animals to overcome their brute enemies, only served to 
make them more desirable game for man, without protecting 
them in the least. The habit of association in large herds, 
also protective under primeval conditions, aoe: s hasten 
their PEN when man came upon the s 
must also take into account the fact that the high 
specialization of ad ee on had probably e family it to the 
a 
various ION of Africa, now so bids disappearing, are 
members of this family as are the decadent bison o 
and the aurochs which was exterminated during cnn 
times. In historic times the American bison has been without 
near relatives on this continent, although fossil bisons are 
found in strata of comparatively recent geological periods. 
It is not possible to say whether these facts have any import- 
ance bearing upon the extermination of the species, but the 
rise and fall of species, genera and larger groups during past 
ages seems to have a biological as well as a geological signifi- 
cance. 
THE BEAVER. 
The beaver although much smaller in size, was extermi- 
nated cited th after the bison. The commercial value of its 
animal, the histor was very gregarious, a ids therefore 
more easily trapped or shot. Had it been more prolific, like 
the muskrat, or more wary, like the gena it would have es- 
ped extermination much longer, but it also was highly 
pecialized for a particular mode of life wherein it had been 
aran secure. 
