WHAT I SAW IN AN ANTS NEST. 341 



nest of the slaves is attacked, the Sanguincas are both bold 

 and wary. Mr. Darwin traced a long file of Sangumeas for 

 forty yards backwards to a clump of heath, whence he per- 

 ceived the last of the invaders marching homewards with a 

 slave pupa in its mouth. Two or three individuals of the 

 attacked and desolate nest were rushing about in wild 

 despair, and " one," adds Mr. Darwin, "was perched motion- 

 less, with its own pupa in its mouth, on the top of a spray 

 of heath, an image of despair over its ravaged home." The 

 picture thus drawn is not the less eloquent because its sub- 

 ject is drawn from lower existence ; although the pains and 

 sorrows of ant life may not legitimately be judged by the 

 standard of human woe. 



The explanation of the slave-making instinct in ants 

 begins with the recognition of the fact that many ants, not 

 slave-makers, store up pupae of other species for food. If 

 we suppose that some of the pupae, originally acquired 

 through a cannibal-like instinct, came to maturity within the 

 nest of their captors, and in virtue of their own inherited 

 instincts engaged in the work of the hive, we may conceive 

 of a rational beginning of the slave-making instinct. If, 

 further, the captors learned to appreciate the labours of 

 their captives, as lightening their own work, the habit of 

 collecting pupae as slaves might succeed and supersede that 

 of collecting them for food. In any case, we should require 

 to postulate on the part of the slave-makers a degree of 

 instinct altogether unusual in insects, or, indeed, in higher 

 animals ; but that such instinct is developed in ants other 

 than slave-makers admits of no dispute. The strengthening, 

 through repetition, of a habit useful to the species, may 

 thus be credited with the beginning of the practice of 

 slavery amongst ants ; whilst special circumstances such 

 as the number of slaves as compared with the number of 

 masters would tend to develop a greater or less degree 

 of dependence of the captors or their servitors. 



Huber, for instance, informs us that the ^7/jz-slaves of 

 the Sangumeas of Switzerland, work with their masters in 



