360 



MANUAL OF ZOOLOGY. 



be mentioned the instinct of making slaves, and that of milking, so to 

 speak, the little Plant-lice (Aphides]. As regards the first of these, it is 

 found that certain Ants possess the extraordinary instinct of capturing the 

 pupae of other species of Ants, and bringing them up as slaves. The 

 relations between the masters and the slaves vary a good deal in different 

 species. In the case of Polyergiis rufescens, for instance, the masters are 

 entirely dependent upon their slaves ; the males and females do nothing 

 except reproducing the species, and the neuters perform no other labour 

 except that of capturing fresh slaves. The masters are in this case unable 

 even to feed themselves, and their existence is maintained entirely by the 

 devotion of the slaves. In Formica sanguined, on the other hand, the 

 number of slaves is much less, and both masters and slaves occupy them- 

 selves in performing most of the duties necessary for the community. The 

 masters, however, go alone when on slave-making expeditions; and in case 

 of a migration, the masters carry the slaves in their mouths. 



A second singular fact in the history of Ants is found in the relations 

 which subsist between them and the Aphides, or Plant-lice. The Aphides 

 secrete, or rather excrete, a peculiar viscid and sweet liquid, by means of 

 a gland which is situated towards the extremity of the abdomen, and com- 

 municates with the exterior by two tubular filaments. Ants are extremely 

 fond of this excretion, and it is a well-established fact that the Aphides 

 allow themselves to be milked, as it were, by the Ants. For this purpose 

 the Ant touches and caresses the abdomen of the Aphis with its antenna, 

 whereupon the latter voluntarily exudes a drop of the coveted fluid. 



The belief that our European Ants stored up grain for winter consump- 

 tion, though generally asserted by the ancients, has been, until recently, 

 discredited by scientific observers, upon the ground that oar Ants are 

 known to be carnivorous in their habits. Mr Moggridge his, however, 

 recently shown that there are exceptions to this rule, and that some of the 

 Ants of the south of Europe (such as some of the species of Alia] not only 

 eat vegetable food, but really execute the feats imputed to them by the 

 old writers. They do, namely, store up a provision of grain for the winter, 

 and they prevent this from germinating by gnawing the radicle; 



ORDER XII. STREPSIPTERA. Females without wings or feet, 

 parasitic. Males possessing the posterior pair of wings, which 



are large, membranous, and 

 folded longitudinally like a 

 fan. The anterior pair of 

 wings rudimentary, repre- 

 sented by a pair of singular 

 twisted organs. Jaws rudi- 

 mentary. 



The Strepsiptera consti- 

 tute a small order, which 

 includes certain parasites of 

 minute size, found on Bees 

 and other Hymenoptera. 

 The female is a soft vermi- 



Fig. 193.- Strepsiptera. Sty lops S pencil, greatly . 



magnified (after Westwood). form grub, Without feet Or 



wings, but with a horny 

 head, which it protrudes from between the abdominal segments 



