572 THE AMERICAN NATURALIST. 
of the long-eared and short-eared owls. To the data of con- 
tents of pellets from the Norway spruce, and arbor vitæ trees, 
and of feeding perches within a radius of an eighth of a mile 
of them, I will add the contents of pellets found at other local- 
ities in the course of this season of observation, and we find 
the following numbers of individuals of different species of mice 
and shrews: Microtus pennsylvanicus, 570; M. pinetorum, 7 ; 
Microtus (undetermined, but probably pennsylvanicus), 26; 
Zapus hudsonius, 3; Peromyscus leucopus, 5; Mus musculus, 
1; Blarina parva, 10; B. brevicauda, 6, and Scalops (?), 1. 
Thus Microtus pennsylvanicus would appear to be the most 
abundant mouse, and Blarina parva the commonest shrew. 
In conclusion, it may be noted that these data add further 
support to the well-proven results of ornithologists, that our 
local owls (with the possible exception of the great-horned owl) 
are of the greatest benefit to the agriculturist. Our three 
commonest local owls, the screech, long-eared, and short-eared 
(as well as the rarer acadian and barn owl), are indefatigable 
destroyers of mice and insects. But since this is the case, and 
since the group of the owls is one of great interest to the natu- 
ralist, it is to be hoped that future students of their dietary 
habits will avoid studying their stomachs for this purpose, and 
in order not to destroy them examine their food pellets instead. 
