INSECTS IN RELATION TO PLANTS 



231 



septa (Fig. 270). They seldom leave the Cecropia plant, unless dis- 

 turbed, and even keep herds of aphids in their abode. The base of each 

 petiole bears (Fig. 271) tender little egg-like bodies ("Muller's bodies") 

 which the ants detach, store away and eat ; the presence of these bodies 

 is a sure sign that the tree is uninhabited by these ants, which, by the 

 way, belong to the genus Azteca. 



It is too much to assert that the ants protect the Cecropia plant in 

 return for the food and shelter which they obtain. All ants are hostile 





FIG. 269. Portion of young stem of Cecropia aden- 

 opus showing internodal pits, a and b. Natural size. 

 Figures 269-271 are from Schimper's Pflanzengeo- 

 graphie. 



FIG. 270. Cecropia adenopus. 

 Portion of a stem, split so as to 

 show internodal chambers and the 

 intervening septa perforated by 

 ants. 



to all other species of ants, with few exceptions, and even to other col- 

 onies of their own species; so that their assaults upon leaf-cutting ants 

 are by no means special and adaptive in their nature, and any protec- 

 ^tion that a plant derives therefrom is merely incidental. Furthermore, 

 hollow stems, glandular petioles and pitted stems are of common 

 occurrence when they bear no relation to the needs of ants. These 

 interrelations of ants and plants are too often misinterpreted in 

 popular and uncritical accounts of the subject. 



The interesting habits of the leaf-cutting ants in relation to the 



