72 HYMENOPTERA. 



what must be considered the perfection of the SjDecies. Such 

 opinions, I feel convinced, are always the result of a super- 

 ficial knowledge of the subject; instances amongst the 

 Formicidce might be cited to prove that in many species a 

 difference of structure is found, so great, that it is at once 

 obvious the functions of the two kinds of workers must be 

 totally diffi rent; in fact, that each kind is totally incapable 

 of performing the duties of the other. I may briefly allude 

 to the genera Ecifon and CEcodoma ; in the latter, the large 

 or soldier-workei's are armed with spines at all points, and 

 have enormous heads, furnished, in some species, with an 

 additional eye, or ocellus, in the middle of the forehead; in 

 JEciton the soldier-ants are furnished with long sickle-shaped 

 mandibles, the small w^orkers having them of an ordinary 

 size; between these there exists no gradation in size, each 

 is structurally fitted to perform a different set of duties, and 

 is incapacitated from exercising the occupations assigned to 

 the other form of sex. 



Wojking honey-bees are apparently proved to be sterile or 

 abortive females; in outward structure, however, no visible 

 difference, excepting size, is obvious; but we do not find 

 here, as amongst the ants, one set of individuals in a com- 

 munity so distinct in form and appearance from the rest, 

 that nothing short of actual observation could lead any 

 naturalist to believe there could possibly exist any con- 

 nection between them. In all the species of ants that are 

 known, the thorax of the worker is diffei-ent in form to 

 that of the female; in the latter it is usually oblong-ovate, 

 whilst in the former it is more or less wedge-shaped, with the 

 thin edge cut off, and the mandibles and antennae are usually 

 more elongated, fitting it for a totally different occupation in 

 the economy of the formicarium. 



