IV PREFACE. 



sing animal and vegetable remains, that, without their 

 invaluable assistance, would contaminate the air and 

 render it death to breathe. We may further observe 

 that insects in their transformations, and in the organ- 

 ization of the larvae, present to the physician, facts, 

 with respect to circulation, worthy of his obser- 

 vation, and which no other class of animated nature 

 would afford him, and thus offer to the physiologist an 

 extensive field, in which his time will not be thrown 

 away, should he direct his attention to it. Of the 

 value and importance of insects we have yet no idea, 

 from the little we know of them. Mr Kirby says, 

 ' ' We have heard that the vaccine disease is derived 

 from the cow and the horse, and the small-pox is said 

 to have originated in the heels of the camel : but neither 

 the ingenious Dr. Jenner ; nor any other writer on this 

 subject has informed us that the rein-deer is subject 

 to the distemper last named. — The inoculator, in 

 truth, is the gad-fly, the tumours it causes are the 

 pustules, and its larvse are the pus." — The lives saved 

 by vaccination would imply the importance of the 

 study of insects. 



Insects are the most numerous, and equally perfect 

 in their structure, with the higher orders of animals 

 in the great scale of creation ; but this is only to be 

 discovered by a close and accurate examination of 

 the originals, collectively and in their several parts ; 

 and following up their adaptation to the habits and 



