SQUIRRELS 55 
which speaks much for the readiness with which such 
animals adapt themselves to new and difficult move- 
ments, and which shows how highly developed those 
parts of the brain must be which are concerned in the 
balancing and kindred functions. I may here correct 
another statement of the same authors. They maintain 
that squirrels do not lap fluids as the dog and cat. 
From repeated observations I know this to be an error, 
so far as the Ground Squirrel is concerned at least. 
It has usually been assumed that squirrels, and 
indeed most rodents, feed wholly on vegetable food, 
and that in those instances in which the contrary has 
been observed, there was evidence of a perverted or 
morbid appetite. Audubon and Bachmann, however, 
state that the Flying Squirrel (Pteromys volucella, Des.) 
has been caught in traps baited with meat. A number 
of writers,* especially within the past few years, have 
drawn attention to flesh-eating habits in several rodents, 
mostly under peculiar circumstances. Some interest- 
ing questions arise in this connection: (1) In how far 
is any rodent carnivorous when abundance of all the 
different kinds of vegetable food that the animal uses 
is at hand? (2) What is the relation between 
confinement and altered appetites? (3) In how far are 
such altered appetites evidence of morbid or perverted 
conditions, and in how far simply the expression of 
physiological needs? The whole subject, I am inclined 
to think, might be placed on a broad and sound 
physiological foundation, but before that can be done, 
many accurate observations are required, and possibly 
also many series of experiments. If we may judge by 
the common house rat, rodents possess unusual plasticity 
as to feeding and other habits, and not less as regards 
their mental life. I found that my Chipmunk would 
* Science, vol. viii; Canadian Naturalist, vol. iii. 
