COMMON FROG. 93 
tongue, the pharynx is contracted, and the air forced into 
the lungs. ‘These organs are of considerable size, lying on 
each side of the anterior part of the vertebral column ; 
they consist of large cells separated by the most beauti- 
fully delicate diaphanous parietes. From this peculiarity 
in the respiration, it follows that it can only be performed 
when the mouth is closed; and that if the mouth be 
gagged open, the animal soon perishes from the cessation 
of pulmonary respiration. 
The ordinary voice of the Frog is too well known to 
require particular description. It is termed croaking, and 
is principally heard during the season of sexual excitement. 
In the spring every one has heard the neighbourhood of 
ponds and ditches, where these animals abound, resounding 
with their loud yet not disagreeable notes. When great 
numbers are congregated together, the noise heard at a 
considerable distance is far from being unmusical, and, 
when associated with the return of the genial season, and 
the calm of a still mild evening, is far more pleasant and 
soothing than many a more fashionable and dearly-bought 
musical entertainment. 
The food of the Frog usually consists of various kinds of 
insects, and of the small species of slug. So voracious are 
its habits during the whole of the season at which it feeds, 
—for, like other cold-blooded terrestrial animals, it passes 
the cold part of the year in entire abstinence,—that it 
might become a most important assistant to the gardener 
or the farmer in the destruction of those pests of the re- 
spective objects of their culture which I have just named. 
It will swallow large coleopterous and other insects whole, 
and will take several of them at a meal. The quantity of 
insects and of slugs, indeed, which would be destroyed by 
encouraging these animals, instead of wantonly and un- 
