4 
, mach not mixing with the Equi and Hamorrhoidales. And thin species I 
believe it is that I have seen out of the stomach at the entrance of the duo¬ 
denum. After waiting with the earnest desire of seeing the fly for about 
ten weeks, one at last made its appearance, a figure of which is given 
i PI. I. ftg. 35, 3(j, and of the larva and chrysalis, fig. 33, 34. In breaking 
no distinct margin to the operculum was observable as in the bovis, but 
simply a giving way to the third joint of the segments. 
I cannot forbear to remark here, that the two short horns at the head or 
small end of the chrysalis, are in fact respiratory tubes, and serve to con¬ 
vey air to the included animal; and when we open the chrysalis we may 
observe two very thin membranous tubes connected with those; which ap¬ 
pear passing down on each side of the head, as though going to the thorax, 
and 1 suspect meet and inosculate with the respiratory foramen.observable 
in the side of the thorax, and is common to all flies. These tubes are, 
however, in the advanced chrysalis broken off; in the recent one they may 
perhaps extend to these foramina, they nevertheless may supply air to the 
cavity after they become ruptured. I notice this fact, and the probable so¬ 
lution.of it, as the circumstance does not appear to have been before 
described or understpod. 
Some of these chrysalises not yielding their flies in due time, I amused 
myself one morning in opening one of them with the point of my penknife, 
by removing three segments from the small end ; some of them were really 
dead, but one being alive, no sooner felt the air and the light, than his head 
began to dilate in a most surprising manner, by some fluid thrown into it 
from the thorax, which again subsided: this was several times repeated, 
till by successive dilatations and contractions he was moved in his shell, 
bursting a fine delicate membrane which enveloped his body, and by 
means of these pulsations, his thoraix w’as at ISngth delivered through the 
opening, when obtaining the use of his legs, he completed his birth by 
crawling to the outside of his coffin and suspending himself there, 
took a survey of this to him new and no doubt extraordinary world, and 
from his dark and loathsome abode in the stomach, was prepared 
to wing the thin air, and live in solar light. His wings, folded up and lim¬ 
ber uext underwent the operation of expansion, and, as it appeared to me, 
from the injection of some fluid into their tubes or nerves, as we consider 
them ; and this I am led to believe, because it appeared to me their gravity 
alone was inadequate to their expansion. This little exercise of the obste¬ 
tric art with the penknife in opening the shell did not in the least dis¬ 
compose the perfect developement pf all the parts of the fly, and may afford 
a hint to those who may wish to be gratified with a view of this singular 
spectacle. 
o 
