398 



^Extracted from the Linnran Society's Journal — 'Zoology,' 

 vol. XX.. 1887.] 



APPENDIX a 



Observations on Ants, Bees, and Wasps. — Part XI. 

 By Sir John Lubbock, Bart., M.P., D.C.L., LL.D., 

 F.K.S. 



[Eead December 1, 1887.] 



On the Relation between Formica sanguinea ai^d 

 ITS Slaves. 



It is well known that Polyei'gus rufescens is entirely 

 dependent on its slaves. Huber long ago found that 

 this ant will starve in the midst of plenty, and will not 

 even put food into its own mouth. I have shown that 

 isolated specimens will live for months if they are 

 allowed a slave for an hour or so every two or three 

 days to clean and feed them. It is said, on the 

 contrary, that our only slave-making species, Formica 

 sanguinea^ can manage without slaves. Indeed, it 

 appears that nests are sometimes found in which there 

 are mistresses alone, entirely without slaves. Forel 

 thinks that he has observed in such nests generally a 

 larger proportion of small individuals than in nests 

 which possess slaves. This would be interesting as 

 tending to show that in such nests the young are less 

 well nourished than when they have slaves to attend 

 upon them. 



The question remains, of what advantage are the 

 slaves to the F, sanguinea? Forel says, I do not 

 quite understand why, * Je ne veux pas trop rechercher 



