470 THE AMERICAN NATURALIST.  [VOL. XXXIIL 
grasshoppers. This negative evidence is of little use. I had 
hoped to be able to make extended observations and perform 
a large series of experiments with caged birds, but have been 
unable to do so, and now can only offer a fragmentary contri- 
bution to this most interesting subject. Orthoptera along the 
Atlantic seaboard, in spite of their protective coloration, are 
fed upon extensively by practically all of our birds, and the de- 
gree of efficiency of their protective adaptation is probably low 
as compared with that enjoyed by many other insects. 
The stomachs sent in to the Department of Agriculture are 
not accompanied with data as to the available supply of insect 
food. This material shows a much greater consumption of 
grasshoppers than I was able to find in stomachs which I 
collected in fields where grasshoppers were not up to their 
usual abundance. Although nestling birds were being reared 
largely upon grasshoppers, the parent birds were feeding upon. 
insects which were less common than the grasshoppers. 
Of the larvae of Lepidoptera, the twig-resembling Geomet- 
ridz, which show a marvelous degree of special protective 
resemblance, are eaten by more than a score of birds of the 
eastern United States. The ground-colored cutworms, that 
so closely simulate the earth in which they live, are eaten by 
practically all the land birds which feed to any extent upon the 
ground. In the middle of May, 1898, I found that birds were 
feeding extensively upon Agrotis. The larve were abundant 
in the earth or under stones, but I saw none crawling about. 
Because of their nocturnal habits and protective coloration it is 
difficult to understand how the birds secured so many of them. 
During June and July, 1898, on a certain farm, I was unable to 
collect many specimens of noctuids and other protectively 
colored smooth caterpillars, but the birds seemed to have no 
trouble in finding them. Later in the season, however, during 
an infestation of Protoparce carolina in a tobacco field, no birds 
were found to select these protectively colored larve. Adult 
Lepidoptera as compared with the larve can hardly be con- 
sidered as forming any significant part of. bird food. The 
smaller inconspicuous moths seem to be relished by caged 
birds. These insects are occasionally preyed upon by the 
