360 GENEEAL ADAPTIVENESS. 



Among ants are to be found two distinct classes or kinds 

 of slaves, viz. 



1. Slaves proper, equivalent to the helots of ancient 

 Greece, the negro slaves of the southern United States, of 

 Cuba or other West Indian islands or possessions, or those 

 that are still kidnapped and sold by the Portuguese in central 

 Africa slaves that are employed as body servants, minister- 

 ing to all the personal wants and comforts of their masters. 



2. Domestic animals equivalent to our milk bine ani- 

 mals subjected to domestication for the sake of saccharine or 

 other fluids or substances they secrete, and of which ants in 

 particular are fond. 



The relation of ant helots to their masters is much more 

 intimate than that of any human slaves usually is to their 

 owner ; for, in certain cases, not the comfort only, but the 

 very existence of the master depends on the service of the 

 slave. Sir John Lubbock tells us that certain slave-keeping 

 ants ' not only cannot clean themselves, but will die because 

 they cannot feed themselves, even when surrounded by the 

 best of food, if the slaves are not there to give it them.' 

 These slaves are indispensable then as nurses to their adult 

 masters ; but they act also as domestic servants, doing all the 

 ordinary household work of the ant-nest. 1 



Of other animals domesticated by ants for the sake of 

 their useful products, the most familiar are Aphides, or plant 

 lice, which yielfl. a much-prized honeydew. Ants own whole 

 4 flocks ' of these plant-lice, which they have subjected to as 

 true and as kindly a domestication as in the case of the 

 common cow by man. The Hypoclinea, a Nicaraguan ant, 

 milks leaf-hoppers, or scale insects, as well as Aphides. Cer- 

 tain other ants keep brown scale insects for the sake of their 

 honeylike secretion. To use Belt's expression, they ' farm ' 

 them, just as we do milch cows. These Aphides and scale in- 

 sects are made to exude their honeydew by stroking their 

 sides with the antennae of their masters, the sagacious ants. 

 Ants also feed beetles for the sake of their saccharine secre- 



1 ' Daily Telegraph ' report and comments on his lecture on ants at the 

 Royal Institution, London, in January 1877. 



