FORMICA. 293 



guinea workers march to a pratensis nest, drive off the latter and 

 steal their large male and female cocoons, which they devoured, 

 but, as he suggests, had they been worker cocoons some of them 

 would probably have been taken home to be brought up as slaves 22 . 



Various authors have recorded finding species of ants, other 

 than slaves, in sanguined nests, and Rothney took D. nigra, D. 

 flava, M. scabrinodis, M. ruginodis, M. lobicornis, Leptothorax 

 acervorum, L. nylanderi, and Tapinoma erraticum in such situations 

 at Shirley 18 . 



In some of these cases no doubt the alien species were living near 

 to the sanguinea, and as Forel has pointed out, what appeared to 

 be mixed nests were really only compound nests. I have twice 

 found a Tapinoma nest quite close to a sanguinea nest at Wey- 

 bridge, in fact the former might almost be described as being 

 situated in the latter, but Tapinoma can well protect itself with its 

 repugnant discharges, and the Formica would leave it strictly 

 alone ; and I have also several times found nests of Myrmica lobi- 

 cornis situated beneath nests of F. sanguinea in the same locality ; 

 and species of Leptothorax, as we have seen, often associate with 

 other ants, but none of these examples represent the phenomenon 

 of dulosis in any way. 



According to Hiiber the slaves are better qualified than their 

 masters to take care of the larvae, and to them is entrusted this 

 important duty ; he also says they close and open the doors of the 

 nest 3 , but we have already seen sanguinea is well able to carry out 

 all these actions unaided. When migrating the masters carry 

 their slaves, and if a nest be disturbed the largest sanguinea workers 

 rush out to see what is happening, threatening with open jaws, the 

 large specimens often acting as sentinels at the doors. I had a 

 large sanguinea worker (recognizable because it had lost one of 

 its antennae) which always undertook these duties. 



The slave-owners spend a large part of their time attending 

 Aphidae on trees and bushes and in hunting small ants and other 

 insects ; I have found amongst other remains in a sanguinea nest 

 the body of a large " Humble Bee." 



It has been suggested that the slaves do not leave the nest of 

 their own free will, and Darwin says that Smith informed him he 

 had never seen the slaves either leave or enter the nest 34 , but 

 this is not always the case. Darwin himself records that during 

 the month of July, 1860, he came across a community with an 

 unusually large stock of slaves, and he observed a few slaves 

 mingled with their masters leaving the nest and marching along 

 the same road to a tall Scotch fir tree, twenty-five yards distant, 

 which they ascended together, probably in search of aphides or 

 cocci 34 . I have frequently seen fusca workers coming in and going 

 out of their owners' nests, and foraging near. 



The winged sexes of sanguinea may be found in the nests from 





