THE YELLOWSTONE NATIONAL PARK. T 
It is interesting to observe, however, that a very large propor- 
tion of the animals here discovered belong to species of wide 
range, or, if more local in their distribution, they frequently rep- 
resent districts far removed. But perhaps the most remarkable 
feature of this distribution is that we find here living, apparently 
under quite similar conditions, representatives of peculiarly 
southern and peculiarly northern types, with some representatives 
of Pacific types.* This opens to view at once a wide field for 
observation upon the habits and economy of a large number of the 
diversified group of insects. 
The stridulation of insects, and the various sexual variations 
and appendages, may all be here studied to the very greatest ad- 
vantage. I might give from my own notes upon these and other 
subjects, taken while deeply engaged in arduous duties of another 
nature, many interesting observations which, in many cases, I was 
absolutely compelled to make, so abundant was the material every- 
where present. 
Fourthly, there would be much to say upon many subjects 
connected with the botany of this region, were it not that its elu- 
cidation has been intrusted to much abler minds than mine. Pre- 
7,800 ft., and th ks wh ititude i ly or quite 10,000 ft., while 
3 J 
te ing the summer months the climate is mild and even cb in the daytime, but in 
clear weather the nights are very cold and frosts are not uncommon. This is due to 
En eine radiation, which, during cloudy nights is, of c rata much less, and the 
mperature conseque å. 
pe full discussion of this very in teresting subject would be out of place in an 
f thi 
si e 
that, while this portion of country is hemmed in on al) sides by high snow-clad walls, 
itis yet the main centre or heart of the aqueous circulation of a vast territory. The 
river channels of the sources of the Missouri, the Columbia, and the Colorado, cut 
through the otherwise impregnable rim of this basin, affording alike an outlet to the 
rains and melted snows, sad an inlet to the insects and other animals which may by 
any means be forced to anter- Thus we may find, at the point from which their sources 
diverge, a few o! f the lower se 
leys Of these. rivers. Were there no barriers of wy kind between these points, w 
p which had sae 
i limated here o: E span eiei along the valleys _ 
of the ot other rivers. The facts show, however, that the representatives | of distant dis 
Park ; 
The natural conclusion, then, is that such park species are the — of acciden- 
tally introduced 
specimens which were hardy enough or fortunate enough to have com- 
plet rier g destroyed in transitu. The great barrier, 
this case, ked by Di Py l believe to be the great plains which inter- 
vene between the head tia lleys of th —— EEE RS perhaps, 
