124 THE INSECT WORLD. 



this liquid at will. This is their secret. A branch of a thistle was 

 covered with brown ants and plant-lice. I observed the latter for 

 some time, so as to discover, if possible, the moment when they 

 caused this secretion to issue from their bodies ; but I remarked that 

 it very rarely came out of its own accord, and that the plant-lice, 

 which were at some distance from the ants, squirted it out with a 

 movement resembling a kick. 



" How did it happen, then, that the ants wandering about on the 

 thistle were nearly all remarkable for the size of their abdomens, and 

 were evidently full of some liquid ? This I discovered by narrowly 

 watching one ant, whose proceedings I am going to describe minutely. 

 I saw it at first passing, without stopping, over some plant-lice, which 

 did not seem in the least disturbed by its walking over them ; but it 

 soon stopped close to one of the smallest, which it seemed to coax 

 with its antennae, touching the extremity of its abdomen very rapidly, 

 first with one of its antennae and then with the other. I saw with 

 surprise the liquid come out of the body of the plant-louse, and the 

 ant forthwith seize upon the droplet and convey it to its mouth. It 

 then brought its antennas to bear upon another plant-louse, much 

 larger than the first ; this one, caressed in the same manner, yielded 

 the nourishing fluid from its body in a much larger dose. The ant 

 advanced and took possession of it. It then passed to a third, which 

 it cajoled as it had the preceding ones, giving it many little strokes 

 with its antennae near the hinder extremity of its body ; the liquid 



came out immediately, and the ant picked it up A 



small number of these repasts are sufficient to satisfy the ant's 

 appetite. (See Fig. 91.) 



" It does not appear that it is out of importunity that these insects 

 obtain their nourishment from the plant-lice. 



" The neighbourhood of ants is agreeable to plant-lice, since those 

 which could get out of the way of their visits, viz., the winged plant- 

 lice, prefer to remain amongst them, and to lavish upon them the 

 superabundance of their nourishment."* 



What we have just related applies not only to the brown (Formica 

 brunnea), but also to the tawny ant (Formica flava], to the ashy black 

 (Formica nigra\ to the fuliginous (Formka fuliginosd), and to a great 

 many more. 



The Red Ant (Formica rnfa) is singularly adroit in seizing the 

 droplet left it by the plant-louse. According to Pierre Huber, it 



* "Recherches sur les Moeurs des Fourmis Indigenes." pp. 181 186. 8vo. 

 Paris, iSio. 



