GENERAL ADAPTIVENESS. 361 



tions. According to Lubbock, 1 * some ants have small blind 

 beetles in their nests, kept there apparently as domestic 

 animals. A kind of small wood-louse also lives with them 

 on amicable terms, much as cats and dogs do with men.' 



' Aphides,' says Belt, ' are the principal ant-cows of Europe. 

 In the tropics their place is taken, in a great measure, by 

 species of Coceidce and genera of Homoptera, such as Membra- 

 cis and its allies.' At least four genera of ants in Nicaragua 

 keep scale insects as we do cows, these genera being Solen- 

 opsis, Pheidole, Pseudomyrma, and Hypoclinea. Solenopsis 

 builds domed galleries, or byres, for the protection of its insect 

 cattle, and otherwise tends them carefully (Belt). Baird, 

 again, mentions the use of Cercopidcs as milk cattle by ants. 



Slavery and domestication, however, are by no means the 

 only forms in which one animal is rendered subservient to 

 the convenience, use, or sport of another a younger or 

 weaker generally to an older and stronger individual. One 

 of the most signal, as well as amusing and instructive, 

 instances of direct subjection of one genus and species to the 

 stronger force of will, greater ingenuity and masterfulness 

 of another is the riding of dogs, horses, asses or pigs, by 

 baboons and other apes or monkeys (Cassell). A cat has 

 been known to make use of a dog's back to get ferried 

 across streams. 



Bullyism petty tyranny is perhaps as common among 

 other animals as in man. Thus one determined horse some- 

 times bullies another (submissive) one into its service by 

 biting, teasing, nagging or driving ; that is to say, it exacts 

 a forced, unwilling, compulsory service. 



In various forms of usurpation certain animals take sel- 

 fish, unfair, and sometimes violent advantage of the labours 

 of others ; and to them are quite as applicable as to man 

 Virgil's lines, well known to every schoolboy, beginning 

 ' Sic vos non vobis.' 



The wars of ants exhibit a number of interesting pheno- 

 mena, including 



1. The use of reinforcements. 



1 As reported in the ' Daily Telegraph ' in January 1877. 



