115 
Genus Parrospus. 
Two specimens of P. longicornis, one from Central and the other 
from Southern Illinois, had eaten nearly twice as much vegetation 
as animal food. The latter consisted chiefly of caterpillars, and in- 
cluded in fact nothing else but traces of plant-lice, eaten by one of 
the two. A little of the vegetation was derived from grass, but the 
source of the remainder could not be satisfactorily traced. 
THE FAMILY AS A UNIT. 
We have now to treat the various collections of Carabide upon 
which this paper is based, as distinct and unbroken groups, without 
reference to the genera of which they are composed. ‘The eighty- 
three specimens of all the species obtained in miscellaneous situa- 
tions, are found to have derived forty-two per cent. of their food from 
the animal kingdom, while the seventy specimens 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 men- 
tioned, 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 collected. This species was eaten 
by sixteen of the seventy beetles, and composed about one-fifth of 
the contents of all the alimentary canals. ‘This accounts, however, 
for only about half the difference noted, the remainder appearing in 
the larger ratios of 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 Carabide. 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 -preserved 
specially for dissection because the circumstances of their capture 
made it seem probable that they were feeding upon vegetation. 
A careful study of the data indicates one interesting and important 
fact with regard to the preferences of this family, namely, that*wheze 
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 vegeta- 
tion only,—a fact which clearly shows that the preferences of the 
Carabide 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. 
