418 Canadian Record of Science. 
June 9th—Tyrant Fly-catcher. Tyrannus Tyrannus. Apho- 
dius fosser. Ichneumon, too much broken for 
determination. 
Some blue jays, Cyanocitta cristata, obtained in the fall, 
had been feeding on beech-mast, one specimen haying swal- 
lowed no less than ten of these sharp-pointed nuts. 
1889. 
March 9th—Blue bird, Sialis Sialis. Carabide, and one Lepi- 
dopterous larvee. 
March 16th—Blue bird. Sialis Sialis. Sumach seed, an 
Orthopteron, Tetigidea polymorpha, and one 
Lepidopterous larve. 
April 5th—White rumped Shrike. Lanius ludovicianus 
excubitorides. Caribidee. 
April 6th—Northern Shrike. Lanius borealis. Carabide. 
April 19th—Cow-bunting. Molothrus ater. Dung beetles. 
Aphodius. Varied wood-pecker. Sphyrapicus 
varius. Small carabide. 
Golden-winged wood-pecker. Colaptes aura- 
tus, Ants. Formica. 
These notes, although by no means as full as I wonld 
wish, are sufficient, I think, to show that the birds did not 
confine themselves to any particular kind of insect, but 
took what they happened to meet with, and would, therefore, 
be as likely to destroy the useful species as those that are 
injurious, and this objection, I think, applies to all animals 
that eat insects, such as toads and frogs, and many of the 
smaller mammals. All of these take the good and bad 
together, and can only be useful in so far as they may be a 
check on the whole race of insects. 
The true check upon injurious insects is the host of para- 
sitic species with which the larve of nearly all butterflies 
and moths and many other noxious species are infested. 
Let us take two well-known species as illustrations: 
