CONCLUSION. 625 



less kinds have sometimes been called spider-flies, from their 

 shape ; such are sheep-ticks QMellophagus ovis), and bat- ticks 

 QNycteribia) . 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 (Pulex) 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 buo-s : its an- 

 tennae are concealed in holes in the sides of its head, like 

 those of certain water-bugs (Nejpa and Belostoma), 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, 



71) 



