254 THE HETERQGYNA. 



This much premised, we may now inquire what are 

 the differences exhibited by these three kinds of Ants, 

 beginning with the workers or imperfect females, as 

 these are constantly to be met with. In these barren 

 individuals we find the head usually large, and the 

 mouth armed with strong mandibles, toothed or rather 

 serrated at their apical margins. The antenna con- 

 sist of twelve joints. The wings are totally wanting, 

 and the thorax accordingly, being only intended for 

 the attachment of the feet, instead of being large 

 and broad, as in most of the Hymenoptera, is elon- 

 gated and narrow, and sometimes composed of three 

 distinct knots, of which the middle one is the 

 smallest. The basal joint of the abdomen, form- 

 ing the peduncle, is dilated behind into a flat scale 

 or elevated knob, which is sometimes the case also 

 with the second segment, and this character, which 

 prevails also in the males and perfect females, will 

 generally suffice to distinguish a species of the tribe 

 of Ants from the other members of its order. The 

 abdomen is of a nearly globular form, usually not 

 much larger than the head, and its apex is furnished 

 with a sting in those species (Myrmica rubra, &c.) 

 which have the abdominal peduncle composed of two 

 segments ; whilst in those in which only a single joint 

 is included in this narrow footstalk, the true sting is 

 wanting, although the poison-glands are present, and 

 to make use of them the insect is compelled to bite 

 the skin of its enemy with its mandibles, and then 

 to inject the poison into the wound thus made, by 

 bending the abdomen forward beneath the thorax. 



The true females present a very different appear- 

 ance from their laborious little sisters, and without 

 actual observation it would perhaps be difficult to 



