DEGRADATION OF STKONGYLOGNATHUS. 85 



slavery, but how they procure the slaves is still a 

 mystery. They fight in the same manner as Polyergus : 

 but yet Schenk, Von Hagens, and Forel all agree that 

 they are no match for the Tetranioriu'ms, a courageous 

 species, and one which lives in large communities. On 

 one occasion Forel brought a nest of Tetraonoriuon 

 and put it down very near one of Strongylogna- 

 thus testaceus with Tetramorium slaves. A battle at 

 once commenced between the two communities. The 

 Strongylognathus rushed boldly to the fight, but, 

 though their side won the day, this was mainly due 

 to the slaves. The Strongylognathus themselves were 

 almost all killed ; and though the energy of their attack 

 seemed at first to disconcert their opponents, Forel 

 assures us that they did not succeed in killing even a 

 single TetramoriuTn. In fact, as Forel graphically 

 observes, Strongylognathus is ' une triste caricature ' 

 of Polyergus, and it seems almost impossible that by 

 themselves they could successfully attack a nest of 

 Tetramorium. Moreover, in Strongylognathus, the 

 workers are comparatively few. Nevertheless, they are 

 always found with the Tetramoriunis, and in these 

 mixed nests there are no males or females of Tetra- 

 moriwm, but only those of Strongylognathus. Again, 

 the whole work of the nest is done by the slaves, 

 though Strongylognathus has not, like Polyergus, 

 entirely lost the power of feeding itself. 



But if the economy of Strongylognathus is an 

 enigma, that of Aner gates is still more mysterious. 



