Community Life in the Animal Kingdom. 25 



nest and in its immediate vicinity. It can hardly be 

 maintained that this posting of sentinels in the dif- 

 ferent parts of the nest was merely due to poly- 

 morphism; for the cognitive and appetitive' powers 

 of the single individual ants of those five species in 

 various ways take a prominent part in it. As we 

 shall show hereafter, the same obtains in other forms 

 of the division of labor in ant states. 



"Social animals perform many little services for 

 each other; horses nibble, and cows lick each other 

 wherever they feel an itching; monkeys hunt for 

 each other's external parasites," etc. Thus Ziegler 

 reproduces the statements of Ch. Darwin. But ants 

 of the same colony are quite as serviceable to each 

 other. Whoever has kept ants in suitably arranged 

 nests of observation, where they feel comfortable and 

 at home, can observe such "acts of charity" a hundred 

 times a day. Every time I gently lift the black cloth, 

 which protects the upper glass plate of the main nest 

 from the rays of the sun, I witness one or more of 

 these lovely scenes. Just now a worker of F. san- 

 guinea is lying immovable, stretched on her side, whilst 

 some of the companions are washing her ; a sanguineay 

 a fusca and a rufiharhis perform this work, and lick 

 her carefully, whilst she continues immovable ; then 

 they turn her around and lick her just as carefully on 

 the other side. After half a minute the light which 

 floods the nest interrupts the performance, and they 

 flee to some darker spot, the patient soon following 

 their example. All the workers of each of the five 

 ant species living in my mixed colony without distinc- 

 tion render these services of cleanliness to one another. 



