318 
ANNUAL REPORT OF NEW-YORK 
which they yield, than for the timber and fuel which we obtain 
from them. 
Many things which are most interesting and remarkable are 
brought to my view, in the researches in which I am occupied 
and I sometimes think there is no kind of mischief going on in 
the world of nature around us but that some insect is at the bot¬ 
tom of it. Certain it is that these little creatures, seemingly so 
insignificant and powerless as to be unworthy of a moment’s 
notice from any body but the curious, occupy a most important 
rank in the scale of creation, and on every side of us their per¬ 
formances are producing most important results, tending probably 
in an equal degree to our benefit in one direction as to our detri¬ 
ment in another. We are accustomed to read with wonder the 
accounts which authors give of the singular habits and amazing 
achievements of these creatures in foreign lands, little suspecting 
that in the fields and woods around our own dwellings, operations 
are constantly going on which are every whit as interesting and 
marvellous. Since my last Report was presented, I have suc¬ 
ceeded in completing the history of an insect whose deeds are as 
astonishing as anything on record in the annals of science. It is 
well known that certain insects have been created apparently for 
the sole purpose of preying upon other insects, and thus restrain¬ 
ing them from becoming excessively multiplied. But I am not 
aware of any discovery hitherto made indicating it to be the office 
of any creature of this class to check the undue increase of any 
of the higher orders of animals. The fact has long been known 
of the squirrels of this country that the males are very frequently 
emasculated, but how this deformity is produced has all along 
been involved in doubt, it being the current popular supposition 
that some of these animals seize and overpower their unfortunate 
fellows and with their sharp teeth reduce them to the condition 
of eunuchs. But I am now' prepared to report a fact which will 
probably set this mooted point to rest. I find we have a species 
of fly, analogous to the bot fly of the horse and the gad fly which 
produces the w r arbles in the backs of cattle, the grub of which 
resides in the scrotum of the squirrel and consumes its testicles. 
Hqw r surprising that an insect should have been called into exis¬ 
tence for the express purpose of executing such a singular work 
as this! 
