( clxxxvi ) 



no such characters at all, except in a negative sense, t. e. in 

 being obsolete or obsolescent. Some $ Ants (as Dorylus) have 

 neither oculi nor ocelli, and the latter are wanting in many 

 workers (= impei'fect females) of this group, and in the ? 9 of 

 most Mutillidae. All these creatures are apterous and live 

 much underground, so that partial or even total blindness may 

 be no great disadvantage to them. The antennae of most ? 

 Pompilidae curl up in a peculiar fashion after death ; but so, 

 to some extent, do those of the $ $, though less so — perhaps 

 only because they are stoviter and less tapering at the apices. 

 The actual joints which curl thus are perfectly simple, and 

 cannot be called paradoxical in either sex. 



(2) In the mandibles, however, we find certain more or less 

 striking special developments, which may be called real sexual 

 characters of a positive kind, and in these we can often recog- 

 nise a probable adaptation to duties which the idle $ escapes. 

 Some $ Aculeates have to excavate burrows in substances at 

 least as hard as wood, chalk, and sandstone — it is even 

 recorded that one Bee has been known to perforate a leaden 

 bullet. In such cases one would expect and one finds 

 mandibles developed for strength and sharpness, and occasion- 

 ally reinforced by special "processes" either on themselves, 

 or on the parts adjoining (genal horn-like projections, dilata- 

 tions of the mandibles at their base, etc.). Again ? $ of 

 Scolia spp. have enormous jaws, which at first sight might 

 seem rap^oJ'i'a^— designed to carry off the large Ce^omo-larvae 

 on which they feed their young. Fabre, however, tells us that 

 in fact these insects do not carry off larvae, nor form burrows 

 for their reception. But the strong development of their 

 mandibles becomes quite intelligible, when we learn from the 

 same author, that Scolia $ $, though they do not make burrows 

 of their own, perform even severer work of a similar kind, by 

 boring (almost like moles) in various dii'ections through hard 

 soil in search of buried Ceionm-larvae, and ovipositing on 

 them when and where they find them. Other Aculeate ? 5 

 use their mandibles raptorially, dragging about victims often 

 much larger than themselves, and in a few cases (Beonbex) 

 crushing and mangling them to some extent with the same 

 organs. Leaf-cutting Bees which also excavate hard wood 



