NATURAL SCIENCES OF PHILADELPHIA. 299 



Alarmed still more by this second intrusion, each seized a larva, 

 studiously avoiding the entrance to the main chamber, and hurried 

 it away to places of security among the adjoining leaves and 

 grasses. I am confident that the main nest was shunned, as the 

 parties passed within an eighth of an inch of it, and could readily 

 have entered, had there been any such intention. 



The conclusions I have to draw from these facts are the follow- 

 ing: 1st. The colony is divided into two sets of neuters, one 

 whose care it is to provide for the wants and security of the abler 

 and more mature, the other to look after the more helpless. 2d. 

 That the more vigorous are necessarily confined to superficial 

 cavities, since they need less care and attention, and in order to 

 avoid the time and trouble of constant removals in consequence 

 of the varied conditions of weather and surrounding circumstances 

 to which they are subjected, said removals seeming to be impracti- 

 cable in view of the weight and size of the fully-grown larvse. 3d. 

 That the young and tender are conveyed to deeper-seated chambers, 

 less likel}^ to be assailed b}^ an enemy, thus afibrding a better means 

 of continuing the species. 



