292 BRITISH ANTS. 



1911, and February, 1912, and on each occasion a sanguinea queen, 

 some workers, and slaves were taken for observation purposes. In 

 August, 1912, pratensis workers were found to be present in the 

 nest, and on completely digging up the same, a deflated pratensis 

 female was found, which must have been adopted by the queenless 

 sanguinea-fusca colony 80 . 



In Britain F. fusca is undoubtedly the usual slave species utilized, 

 indeed I have never found any other fusca form present in sanguinea 

 nests in nature, and only once any other slave ; when at Rannoch I 

 took specimens of F. rufa var. alpina in company with fusca in a 

 sanguinea colony situated in a locality where alpina nests occurred 75 . 



F. Smith says he has found cunicularia in sanguinea nests in Eng- 

 land 16 , though he gives no dates or localities for the same, but there 

 is no reason why this should not be the case, for sanguinea enslaves 

 the fusca species that happens to be living in the same district. 



I have placed in my sanguinea observation nests worker cocoons 

 of F. fusca, glebaria, rufibarbis, rufa, and pratensis, all of which have 

 been taken into the nests, some of each having been allowed to 

 come to maturity and act as slaves. 



D. Sharp says that sanguinea " possibly utilizes Lasius flavus " 

 as a slave in England 44 ; he probably made this statement because 

 F. Smith has published that he had found flava workers in san- 

 guinea nests 16 . In 1843 the latter author records that one evening 

 he saw some sanguinea workers pillaging nests of D. nigra and D. 

 flava at Cove Common, carrying off their workers and pupae ; 

 this he concluded was a slave-raid 4 ; and Schenck says he has found 

 D. aliena workers and pupae in sanguinea nests at Nassau 10 . Forel 

 criticizes the belief of Schenck and Smith that sanguinea makes 

 slaves of aliena and flava pupae, remarking that this was a com- 

 plete error, sanguinea always devouring the Donisthorpea pupae 

 given to them 24 . 



Forel further points out that sanguinea workers often attack 

 nigra and flava nests and amuse themselves by killing the inhabi- 

 tants 24 , and Wheeler writes : " Even sanguinea shows a tendency 

 to lapse into the ancient instinct of plundering the nests of different 

 species of ants indiscriminately " ; he describes as ridiculous a 

 foray of a large sanguinea rubicunda colony on a woodland variety 

 of Myrmica scabrinodis he witnessed in America 52 . 



On July 10th, 1912, I myself observed an attack by sanguinea 

 on a colony of D. umbrata at Weybridge, the nest of the latter 

 being situated under a gorse root some twelve paces away from 

 that of the former. A row of sanguinea workers stood outside the 

 umbrata nest on guard, while others had penetrated under the root, 

 and a large number of dead umbrata were lying about, and many 

 of the sanguinea had dead workers of the attacked species fastened 

 to their legs and antennae 76 . 



Forel records that one fine day he saw a thick column of san- 



