22-| ANTS. 



cover. Vpon pulling any of these apart a small flat scale in great 

 numbers will be found " adhering to the leaf. Upon another species 

 of tree, .Icaciu say, perhaps ' hoppers' only of a particular kind, with 

 honied head, and their larvae and pupa? may he found." 



The striking character of the tents described in the preceding para- 

 graph leads naturally to the question of their function and of the 

 instincts of which they are an expression. There are several possible 

 answer- to such a question. We may suppose that the tents are built, 

 first, for the purpose of preventing the escape of the aphids and 

 coccids to other plants or to other parts of the same plant; second, 

 for the purpose of protecting these insects and the ants themselves from 

 exposure to cold, air-currents, moisture, or light; third, for the pur- 

 pose of protecting the aphids and coccids from their natural enemies 

 or from other ants. For some or all of these purposes the tents would 

 seem to be admirable contrivances. It is probable that the aphids and 

 coccids make the same appeal to the ants' sense of ownership as their 

 own larvae and pupa?. This is certainly true of some ants, like our 

 species of Lasins which are fond of cultivating snow-white root aphids 

 and coccids in their subterranean galleries. Whenever the stones cov- 

 ering the nests are overturned, the workers seize their charges in their 

 mandibles and hurry away with them to a place of safety. It is nat- 

 ural, therefore, that ants should try to prevent the escape of their 

 charges from a sense of proprietorship such as all ants display towards 

 their own brood. Protection of the ants themselves from the air, and 

 especially from the sunlight, is of great importance while they are 

 waiting among the plant-lice for the accumulation and excretion of the 

 honey-dew. Indeed, few of the species known to construct pavilions 

 are at all fond of the open sunlight. This is certainly true of many of 

 those mentioned in the preceding paragraphs. We may infer, there- 

 fore, that the ants probably build tents primarily for their own comfort 

 and protection. 



In concluding this chapter attention must be called to the fact that 

 ants which have become parasitic on other species tend to lose com- 

 pletely the ability to excavate or construct nests. It is believed that 

 even Formica sanguined, which is only slightly dependent on its 

 slaves, shows an inclination to neglect the labors of excavating. More 

 completely parasitic genera, like Polycryns, though still possessing 

 worker forms, are able to dig in the earth with their fore feet when 

 opening up the galleries of the ants whose brood they are robbing, but 

 they leave the construction of the nest entirely to the slaves. In highly 

 parasitic genera, such as . lnc>'</ates, Wheeleriella, etc., which have no 

 worker forms, nest-building is, of course, a long-lost art. 



