BIRDS, CATERPILLARS, AND PLANT LICE, 119 
not be identified in the stomach of a bird. Orioles, Vireos, 
and Titmice are among the birds that commonly dissect 
caterpillars in this way. This is not a rare or exceptional 
habit, nor is it difficult to observe. It seems to be a device 
adopted by certain of the smaller birds mainly when feeding 
on caterpillars too large to be swallowed whole without caus- 
ing some inconvenience; therefore, they choose the parts 
which can be digésted readily, and reject the others. 
There are two facts which have gone far to justify the con- 
clusions of those who believe that birds do not eat hairy cat- 
erpillars; they are: (1) most birds appear to prefer hairless 
caterpillars with which to feed their young; (2) when small 
hairless caterpillars are abundant, most birds seem to prefer 
them to large hairy caterpillars. The first statement may 
be accepted as a rule; nevertheless, fifteen species of birds 
were seen by my assistants in the act of carrying away hairy 
larvee apparently to feed their young, and some of these were 
actually seen to put large hairy caterpillars down the throats 
of the young birds. These fifteen species are: the Robin, 
Wood Thrush, Catbird, Chickadee, Chestnut-sided War- 
bler, Yellow Warbler, Black and White Warbler, Yellow- 
throated Vireo, Red-eyed Vireo, Scarlet Tanager, Crow, 
Blue Jay, Baltimore Oriole, Black-billed Cuckoo, and Ycl- 
low-billed Cuckoo. Statement No. 2 is proved by records 
made by several observers, in years when cankerworms 
were abundant. They found that when birds had for some 
time been feeding on the hairy caterpillars of the gipsy moth 
they neglected these larve, for a time, at least, to feed on 
the young cankerworms. While the above observations 
show that the hairy caterpillars are not so eagerly sought 
after by most birds as are many hairless kinds, and that the 
hairy species enjoy seasons of partial immunity from the at- 
tacks of birds, they form no adequate excuse for the sweep- 
ing, erroneous generalizations regarding this subject that 
have been given a wide circulation. 
If we turn to the literature of economic entomology, we 
shall find many records which are corroborative of my state- 
ments. The occurrence of the great flight of Starlings and 
other birds that flocked to feed on the caterpillars of the nun 
