THE WEB OF LIFE 357 



difficult. Darwin's suggestion was that many ants cap- 

 ture the pupa3 of other ants for food, that some of the stored 

 pupse might be unintentionally reared, that if their pres- 

 ence in the community was not resented but proved use- 

 ful, the slave-making habit might gain ground. ' If it 

 were more advantageous to this species to capture 

 workers than to procreate them, the habit of collecting 

 pupse, originally for food, might by natural selection be 

 strengthened and rendered permanent for the very differ- 

 ent purpose of raising slaves '. 



Dr. Dublin makes a supplementary suggestion, that we 

 must start from the adoption of the newly fertilized queen 

 of the slave-makers by the workers of an impoverished 

 and queenless colony. He refers to Santschi's observations 

 on a Tunisian ant, Bothriomyrmex, which temporarily en- 

 slaves the workers of a species of Tapinoma. The young 

 queen B was taken into the nest T, where aided or unaided 

 she killed the queen T, and proceeded to lay eggs. The 

 workers of T reared the larvse of B, but as the slaves died 

 off the community became pure B and self-sustaining. 

 If the ranks of the slaves had been recruited by plundering 

 neighbouring colonies, then slave-making might have been 

 established. If therefore we take together the tendency of 

 the young queen to enter an established nest, the tendency 

 some kinds of workers show to welcome a young queen 

 foreign to their race, and the common habit of capturing 

 the pupae of other species, we have a basis for understanding 

 slave-keeping. 



Man and the Web of Life . We must end this chapter, 

 as we began it, by emphasizing the practical importance 

 of the conception of the web of life. In securing his 

 own welfare and that of his stock Man must keep the 



