THE DEGENERATE SLAVE-MAKERS. 



499 



and has the gaster of normal dimensions, but with a longitudinal dorsal 

 groove before fecundation. After entering the Tetramorium nest, 

 however, the ovaries become greatly enlarged and the gaster expands 

 till it bcomes a flattened sphere 4 mm. in diameter, on which are seen, 

 in the form of little plates, isolated by the enormous distention of the 

 articular membranes, the strongly chitinized rings, which, in the virgin, 

 constitute the whole external surface of the gaster. Both male and 

 female have ii-jointed antennae and large ocelli, but the eyes are rather 

 poorly developed. Owing to the apterous condition and sluggish move- 

 ments of the male, mating takes place in the nest among the offspring 



FIG. 279. Anergates atratulus. (Original.) a, Virgin female: b. old queen; 

 of same ; d. pupoid male ; e, head of- same. 



head 



of the same mother (adelphogamy). This can be readily observed 

 both in natural and artificial nests. The couples are so firmly united 

 that they can be killed, without separating, in warm alcohol. After 

 fecundation the females fly out of the nests, so that the nuptial flight, 

 though vestigial and unisexual in this ant, still subserves the important 

 function of disseminating the species. Tetramorium colonies infested 

 with Anergates contain only the workers of the host species. Adlerz 

 and Wasmann have shown that these pay very little attention to the 

 virgin Anergates, but carry the males about and lick them assiduously, 

 and that during these operations the latter assume a characteristic, 

 motionless attitude. Both the male and female parasites are, of course, 

 fed by their hosts, as they are quite unable to eat independently. 



