252 THE ACULEATE HYMENOPTERA. 



ovipositor of the preceding tribe. The antennae are 

 rather short, composed of thirteen joints in both sexes, 

 and elbowed at the extremity of the long basal joint ; 

 the wings exhibit comparatively few veins ; and the ab- 

 domen, which is of an oblong form and attached to 

 the thorax by a very short peduncle, is so concave 

 beneath, that the insects can roll themselves up into 

 a ball, an attitude which they often assume when 

 threatened with an attack by the Bees, into whose 

 cells they are bent upon introducing a spurious pro- 

 geny. In their general form, in the structure of 

 their antennae, and even, to a certain extent, in that 

 of their sting or ovipositor, they exhibit a marked 

 affinity to the aculeate or stinging section of the peti- 

 olated Hymenoptera, to which we must now turn our 

 attention. 



As already stated, the most important difference 

 between the Aculeata and the preceding insects, con- 

 sists in the possession by the former of poison-glands 

 connected with the ovipositor, which thus becomes not 

 merely a passage for the egg, but a most formidable 

 offensive weapon. This is not, however, the only cha- 

 racterof union presented loyiheAculeata, the antennae 

 are almost invariably composed of twelve joints in the 

 females and of thirteen in the males, the wings are 

 always veined and furnished with distinct cells, and 

 the abdomen consists of six segments in the females 

 and of seven in the males. 



The first tribe of this section includes the various 

 species of true Ants, whose singular ceconomy has 

 been in all ages the object of admiration, and whose 

 exemplary industry has so often been held up to the 

 imitation of mankind, at all times perhaps rather too 



