ORIGIN OF THE STING. 15 



of Formica represents a hitherto undeveloped organ, 

 then the original ant was stingless, and the present 

 stings of ants have an origin independent of that 

 belonging to the other aculeate Hymenoptera, such 

 as bees and wasps. These organs, however, are so 

 •complex, and at the same time so similarly constituted, 

 that they must surely have a common origin. Whether 

 the present sting is derived from a leaf-cutting instru- 

 ment, such as that from which the sawfly takes its name, 

 I will at present express no opinion. Dr. Dewitz him- 

 self regards the rudimentary traces of wings in the 

 larvae of ants as the remnants of once highly-developed 

 organs ; why, then, should he adopt the opposite view 

 with reference to the rudimentary sting? On the 

 whole, I must regard the ancestral ant as having pos- 

 sessed a sting, and consider that the rudimentary con- 

 dition of that of Formica is due to atrophy, perhaps 

 through disuse. 



On the other hand, it is certainly, at first sight, diffi- 

 cult to understand why ants, having once acquired a 

 sting, should allow it to fall into desuetude. There are, 

 however, some considerations which may throw a certain 

 light on the subject. The poison glands are much larger 

 in Formica than in JNIyrmica. JNIoreover, some species 

 have the power of ejecting their poison to a consider- 

 able distance. In Switzerland, after disturbing a nest 

 of Formica rufa, or some nearly allied species, I have 

 found that a hand held as much as 18 inches above the 

 ants was covered with acid. But even when the poison 



