604 
that certain stages of improvement are especially favorable for 
these species, these conditions exist in only a part of the county 
at a time, and are balanced by unfavorable ones elsewhere. 
In general there has been a uniform diminution of fur-bearing 
animals from the first. The exception we note, is that of the musk- 
rat. Of late years, owing to the low value of their skins and to the 
general prosperity and consequent increased means of earning 
money, the muskrats have not been so extensively trapped as 
formerly, and I believe that they are at least holding their own in 
the county. At present the improved drainage and increased use 
of underground drains are the most unfavorable conditions for the 
species. 
In the case of bats, so far as available data go, the favorable and 
unfavorable changes—for example, destruction of birds of prey, on 
the one hand, and removal of forests, on the other—about balance; 
and while there must have been some fluctuations in the number of 
the bats in the county from year to year, and probably permanent 
variations in the relative abundance of the species, on the whole the 
number present now does not differ greatly from what it was a 
century ago, nor do we know of any great waves of increase or 
decrease since the first settlement of the country. 
In the case of the smaller rodents—gophers, rats, and mice— 
there has probably been a continued increase from the first perma- 
nent coming of white men. The reason is evident. Man has 
furnished abundant food for these animals.and has destroyed their 
worst enemies. 
Buffalo and elk were wholly exterminated by hunters, and the 
beaver nearly so, before the first settlement in the county. The 
squatters and early settlers destroyed the larger Carnivora in self- 
defense, and this was followed during the earlv settlement and 
improvement stages by an increase of deer, opossum, and such 
smaller carnivores as raccoons, foxes, skunks, and weasels. As these 
smaller Carnivora are themselves diminished by man’s persecution, 
the rabbits and smaller rodents increase, and this increase continues 
tll a high degree of cultivation is attained. In the final stages of 
village and city all the Mammalia disappear except the bats—which 
remain in little-changed numbers—and the rats and mice, which 
are continually increasing. 
