I 1 he Food Relations of the Carabidce and Coccinellidcc. 
47 
captured in the orchard so often mentioned took seventy-seven per 
cent, of their food from the same sources. The individuals from 
the cabbage field, however, show no such excess of animal food 
as those just mentioned, the ratios standing for them at forty-one 
per cent. If we seek to account for this striking surplus shown 
by the second group, we shall find, in the first place, a difference 
of more than sixteen per cent, between the ratios of insects eaten 
by the first and second groups respectively- — a fact clearly due to 
the presence of canker-worms where the second group was col- 
lected. This species was eaten by sixteen of the seventy beetles, 
and composed about one-fifth of the contents of all the aliment- 
ary canals. This accounts, however, for only about half the dif- 
ference noted, the remainder appearing in the larger ratios of the 
other insects, of mollusks, of earth-worms, and of undetermined 
animal food. 
This indicates either that other forms of animal life than the 
canker-worms were superabundant in the orchard, or else that the 
miscellaneous collections do not correctly represent the ordinary 
food of the Carabidae. The truth probably lies between the two. 
The extraordinary wetness of the season, together with the amount 
of rubbish on the ground in the orchard, gave these beetles an 
unusual opportunity to capture slugs and earth-worms, and 
afforded excellent harborage for all sorts of insects. On the 
other hand, many of the beetles from other situations were pre- 
served especially for dissection because the circumstances of their 
capture made it seem probable that they were feeding upon veg- 
etation. 
These tables indicate one interesting and important fact with 
regard to the preferences of this family, namely, that where an 
extraordinary abundance of any kind of animal food appeared, 
with a consequent increase in the percentage of that kind appro- 
priated by the beetles, this increase was compensated, not by a 
decrease in the other animal elements, but in the ratios of vege- 
tation only — a fact which clearly shows that the preferences of 
the Carabidae are for animal food. It should be noticed, however, 
that this argument does not apply to all the genera, as is seen, 
for example, by recalling the record of Anisodactylus. The ten 
specimens of this genus taken in the orchard had eaten much 
more vegetation than the nineteen from various other places. 
