CONCLUSION. 
625 
less kinds have sometimes been called spider-flies, from their 
shape ; such are sheep-ticks ( Mellopliagm ovi£), and bat-ticks 
(. Nycteribia ). These singular creatures are not produced 
from eggs, in the usual way among insects, but are brought 
forth in the pupa state, enclosed in the egg-shaped skin 
of the larva, which is nearly as large as the body of the 
parent insect. This egg-like body is soft and white at first, 
but soon becomes hard and brown. It is notched at one 
end, and out of this notched part the enclosed insect makes 
its way, when it arrives at maturity. 
The flea QPulex') may almost be considered as a wing- 
less kind of fly. Its proboscis seems to be intermediate 
in its formation between that of flies and of bugs ; its an- 
tennas are concealed in holes in the sides of its head, like 
those of certain water-bugs ( Nepa and JBelostoma), and 
somewhat resemble them in shape ; while the transfor- 
mations of the flea are not very much unlike those of 
the flies, whose maggots cast off their skins on becoming 
pupae. 
Having now arrived at the end of my work, I have only 
to add a few remarks by way of conclusion. It has been 
my design to present to the reader a sketch of the scien- 
tific arrangement of the principal insects which are inju- 
rious to vegetation, not only in New England, but in most 
of the United States. The descriptions of the insects, being- 
drawn up in familiar language, will enable him to recognize 
them, when seen abroad, in all their forms and disguises. 
The hints and practical details, scattered throughout the 
work, it is hoped, will serve as a guide to the selection 
and the application of the proper remedies for the depre- 
dations of the insects described. I regret that it has not 
been in my power to do full justice to this important sub- 
ject, which is far from having been exhausted. My object, 
79 
