SLAVE-MAKING ANTS. 



433 



absolutely helpless without them. Those who have observed 

 the manners and customs of these Ants say that the relative 

 behaviour of the two species is most curious. The masters can 

 scarcely even feed themselves, much less go i n search of food. 

 The experiment has been made of putting into a glass case a 

 number of the master Ants, together with a portion of the nest, 

 with food and all needful requisites. The Ants were ludicrously 

 helpless, running about in a purposeless sort of manner, and not 

 having the least idea what to do. After their incapacity had 

 been proved, a single slave was admitted, when the whole state 

 of things was changed. The slave— a mere dwarf among giants 

 — treated the master Ants as a nurse would treat a number of 

 children, fed them, and then began to rebuild the damaged nest. 

 The accompanying illustration depicts one of these slave- 

 making species, Polyergus rufescens, one of the Ants being shown 

 as carrying in its jaws the 

 pupa of a slave. The rela- 

 tive size of master and ser- 



vant is thus shown, the slave 

 being scarcely larger than 



our common Eed Ant. It is 



a European species, and is 



common in France. The 



jaws of this species are very 



slight and feeble, so that the 



insect isphysically incapable 



of doing the work which 



generally falls to the lot of 



Ants who have to make 

 their own nest, find their 

 own food, and nurse their own young. Mr. Darwin makes 

 much use of this phenomenon in his well-known work on the 

 " Origin of Species." 



The following account of a slave-making Ant is contributed 

 by Mr. W. H. Dale to the " American Naturalist," and is valu- 

 able both as showing that division of labour is employed among 

 Ants, and that the slaves can be sent from one place to another 

 by the order of their masters : — 



"It was growing rather dark in the dense thicket, and I 

 retraced my steps towards the beach. On my way I added 



F F 



Fig. 221.— Polyergus rufescens. 

 (Red-brown.) 



