14 THE DISPEESION OE THE GIPSY MOTH. 
of the Japanese robin they were placed inside the larva? of the meal 
beetle (Tenehrio molitor), while those fed to the screech owl were 
inserted in a freshly killed mouse. 
Of 52 eggs that passed through the Japanese robin three hatched, 
while of 112 eggs vomited by the screech owl with the remains of the 
mouse seven hatched. Xo hatching resulted in the experiments with 
the other birds. 
The writer says : 
To sum up the details of these various experiments it is seen that gipsy- 
moth eggs can withstand the action of the digestive fluids of birds belonging 
to at least two families, TurdicUe and Bubonida?. without suffering any. or 
only slight injury. In regard to the large family, Fringillidae, also an insec- 
tivorous group, I am inclined to believe that these birds might also occasionally 
distribute gipsy-moth eggs in spite of the negative results obtained in my 
experiments. 
These conclusions seem too sweeping because of the large per- 
centage of the eggs that failed to hatch, and when the conditions 
under which the birds were fed is considered it is doubtful whether 
comparable results would be secured under natural conditions. 
The Bubonida? and Fringillidse are not, for the most part, in- 
sectivorous birds, and it is doubtful if the latter would, except in 
rare instances, eat eggs without crushing them or at least attempting 
to break away their outer covering, as this is their usual habit when 
feeding o*n seeds, which are their natural food. 
Whether eggs would pass through the alimentary canal of some of 
our less domesticated insectivorous birds unharmed is an open ques- 
tion, and one very difficult to settle, owing to the fact that these wild 
species can not be experimented with in confinement in any satis- 
factory way. It should also be noted that the digestive process in 
birds is more rapid under natural conditions than when they are 
confined for experimental purposes; hence it may be that in nature 
a larger percentage of eggs would withstand the digestive action, 
but the distance that they could be carried would be correspondingly 
reduced. The main question, however, appears to be whether birds 
actually eat eggs of the gipsy moth in the field. 
Men engaged in the moth work frequently find egg clusters which 
have been broken, and sometimes in such a condition that one might 
conclude that they had been pecked at by birds. Clusters are 
sometimes broken by squirrels or other animals, and not infrequently 
this is charged up to birds. Mr. John A. Farley, one of the agents 
of the Massachusetts State forester's office, reports the following ob- 
servation, which shows how carefully matters of this nature must 
be investigated in order to prevent error. On visiting a wooded 
area where it had been reported that birds were feeding on gipsy- 
moth eggs and where the clusters showed every indication that this 
