Wars and Slavery in the Animal Kingdom. 73 



A similar colony I recently detected near Luxemburg, 

 1904. On May 23, 1889, I met with the opposite 

 extreme, namely, a very weak sanguinea colony, in 

 which the slaves were about twenty times more 

 numerous than their masters. These extreme cases 

 are, however, very rare. Besides, it is plain that the 

 number of slaves in different colonies changes every 

 year; and lastly, the number of slaves in the nests of 

 the sanguine slavemakers depends also on special, 

 local circumstances. Where slave nests are very 

 numerous, e. g., in groves of birches and oaks, there 

 more slaves will be found in the sanguinea nests than 

 on the open heath, where fusca nests are very scarce. 

 Yet, ceteris paribus, we find the constant law, that in a 

 given sanguinea nest, the number of slaves and that of 

 masters is not in direct but in inverse proportion. My 

 observations of sanguinea nests in Dutch Limburg, 

 Rhineland, Vorarlberg, Bohemia and Luxemburg, 

 everywhere confirmed this law. 



How is this remarkable difference between the col- 

 onies of sanguineas and of Amazons to be explained? 

 The latter possess the more slaves, the more populous 

 the colony ; with the former we meet the reverse. This 

 difference is explained by the fact that F. sanguinea 

 is not, like the Amazons, essentially dependent on her 

 slaves, but rather regards them, as it were, as a 

 secondary complement of her own communities. The 

 sanguineas rob and rear only as many slave pupae, as 

 is suitable for their colonies. Weaker colonies thus 

 feel greater need of supplementing their own deficiency 

 by adding auxiliary fofces, whereas stronger colonies 

 do not feel the same necessity; so they regulate their 



