INSECT CHANGES. 163 



province it is to remove the injurious sub- 

 stances adverted to, should be wholly employed 

 in this work. Accordingly we find these mag- 

 gots in a state incapable of reproduction, and 

 endued with what they require — an insatiable 

 desire for constant feeding, and proportion- 

 ate digestive organs. They pass into another 

 condition before they begin the reproduc- 

 tive processes, which must interrupt their ope- 

 ration of constantly feeding on the supera- 

 bundant and injurious matters "which would 

 otherwise destroy the healthiness of the air 

 we breathe. The larva, therefore, has no pro- 

 pensity but a constant appetite for food, and 

 is the longest state of insect life. After 

 tliis it is changed into a condition of inacti- 

 vity, wherein, by certain slow processes, the 

 perfect fly is formed, and subsequently dis- 

 closed, not to feed with the voracity of its 

 maggot, but to lay multitudes of eggs in 

 places suitable for the development of more 

 larvae. The object of its existence having 

 been thus answered, it dies. Who can think 

 of these marvellous transformations, and not 

 admire the wisdom and power of God,- nor 

 Ml to remember for himself, that, before he 

 can perform the services of a better world. 



