ANERGATES. 91 



queen mother), with the gaster enormously distended, and a 

 number of Anergates larvae and pupae. 



Aner gates is only found in the nests of T. caespitum. In such 

 Anergates-Tetramorium colonies no males, females, nor brood of 

 the host species occur, and Schenck 1 who discovered the species in 

 Nassau, perhaps naturally took the Tetramorium workers, with 

 which the Anergates occurred, to be those of the latter. 



The male of this ant is a most curious object ; it walks with 

 difficulty, looking like a cripple, and both it and the female are 

 fed by the Tetramorium workers they are unable to eat without 

 assistance. The males are licked and carried about by their hosts, 

 but very little attention is paid to the virgin females by the latter. 

 Mating takes place in the nests between brother and sister (adelpho- 

 gamy), after which the females fly away, presumably to seek 

 other Tetramorium nests ; though after fecundation, they soon 

 get rid of their wings in captivity. 



The abdominal segments expand enormously some time after 

 the female has lost her wings, becoming so distended with eggs 

 that the chitin which had previously formed segmented rings, is 

 now represented only by small black bars separated by broad 

 spaces of white membrane. 



The Tetramorium workers in these mixed colonies are generally 

 large in size, and dark in colour, showing that they have sprung 

 from an old established colony. On June 12th, 1913, I found a 

 colony of T. caespitum on the Isle of Lundy 25 , which contained no 

 brood nor queen (whereas in other nests on the Island sex-pupae 

 and a dealated female were found), the workers being the largest 

 specimens I have ever seen, and very dark in colour. This might 

 well have contained a dealated Anergates female, but the ground 

 being very hard and stony, it was impossible to dig up the nest 

 properly. 



The males and winged females which are sometimes very 

 numerous, especially the latter have been found from May to 

 August. Adlerz has described two extraordinary Gynandromorphs 

 which he reared in an Anergates-Tetramorium colony he had taken 

 in Sweden, and established in an observation nest, as follows 16 : 



1. Imperfect lateral gynandromorph, with the head largely male on the 

 left, female on the right side, the light colour of the male being sharply 

 marked off only anteriorly from the dark colour of the female. Thorax female in 

 front, with wings equally developed on both sides, but with pale coloration 

 on the left and dark coloration on the right, the line of division neither 

 sharp nor straight and the whole postscutellum blackish brown. Abdomen 

 with irregular arrangement of colour. Petiole black on the right, greyish 

 yellow on the left ; post-petiole mostly blackish brown, but with a large 

 greyish yellow spot on the left side of its anterior surface. Third dorsal 

 tergite blackish brown on the right, yellowish on the left side, the remainder 

 of gaster greyish yellow tinged here and there with pale brown. Third 

 tergite with a median longitudinal groove which runs back on to the succeed- 

 ing segment as in the virgin female. The left side of the abdomen has seven 



