28 
with great solicitude and care her office of depositing the eggs on 
the legs of the Horse, in the manner we have already stated ; 
thus completing the wonderful round of its operations and his¬ 
tory, which sometimes I have thought might not afford a subject 
altogether unworthy of the poet s pen, being novel, innocent, and 
full of singular incident; and if mingled with the probable designs 
of an all-wise Providence in thus providing for them, and then- 
probable benefits to the animal in return for their habitation, and a 
description of the dangers and solicitudes attending the process 
of their birth and breeding: the rural scenery of the places ot 
their resort, and of these exploits, and with useful reflections 
arising from such incidents, it might be rendered perhaps, in 
good hands, not destitute of interest and amusement. 
There is considerable difference in the male and female Fly; the 
extremity of the abdomen in the one is obtusely abbreviated, in 
the other drawn out to a style or horny tube of some length, for 
the more convenient depositing the eggs and applying them to the 
hair.—See fig. 1. PI. I. 
The perfect Fly but ill sustains the changes of lveather ; and 
cold and moisture, to any considerable degree, would probably 
be fatal to it. It is remarkable these flies never pursue the horse 
into the water. This aversion I imagine arises from the chilness 
of that element, which is probably felt more exquisitely by them, 
from the high temperature they had been exposed to during their 
Larva state in the body of the animal. The heat of the stomach 
of the horse is much greater than that of the warmest climate, 
being about 102 degrees of Fahrenheit, and in their fly state they 
are only exposed to 60, and from that to about 80 degrees. This 
change, if suddenly applied, would, in all probability, be fatal 
to them ; but they are prepared for it, by suffering its first effects 
in the quiescent and less sensible state of a Chrysalis. I have 
often seen this Fly during the night-time, and in cold wea¬ 
ther, fold itself up, with the head and tail nearly in contact, 
