SCIUROPTERUS VOLUCELLA. 
103 
The modifications of structure that adapt it to its habit of life 
are by no means so great as in the case of the mole or bat, and yet 
it is not less inseparably associated with an almost exclusively 
arboreal existence than are these others with the special conditions 
of their environment. 
Flying Squirrels make their nests in the hollows of trees, 
frequently taking possession of deserted woodpecker’s holes. They 
are easily aroused and driven out by hammering against the trunk. 
I have thus expelled the occupants of as many as half a dozen nests 
in a single day’s hunt. Their progeny must be brought forth early 
in April, for on the 30th of April, 1878, Dr. C. L. Bagg and myself 
took three half-grown young from a woodpecker’s hole, about fifteen 
feet above the ground, in a decayed stub. They did not seem at 
all frightened, but were tame and gentle from the beginning, and 
my sister and I kept two of them alive. At night they were ex- 
cessively active and playful, but, unless disturbed, would sleep 
during the greater part of the day. They preferred to remain 
upon our persons, and one used to sleep in my pocket. At first it 
could jump but a short distance, and if placed upon a chair or table 
became very unhappy and would come to the edge nearest the 
place where I was standing and cry to be taken. If I extended 
my arm and approached it, the little creature, trembling with 
delight, would stand on its hind legs and leap upon my hand ; 
thence, either running up my sleeve or down my neck, it would 
nestle in my bosom and sleep for hours, or until forcibly removed. 
Prof. F. H. King, in a recent communication, records an experience 
with the young of this species that calls to mind many of the actions 
and peculiarities of those that I have had. He says : “ I have never 
known wild animals that became so perfectly familiar and confiding 
as these young squirrels did ; and they seemed to get far more 
enjoyment from playing upon my person than in any other place, 
running in and out of pockets, and between my coat and vest. 
After the frolic was over they always esteemed it a great favor if 
