208 Psyche [October-December 



Dissection of a number of Diacamma workers and especially 

 of the mating worker supports the inference that only one indi- 

 vidual in a colony assumes the reproductive function at a time. 

 Unfortunately the material had been in rather weak alcohol for 

 several months and the very hard chitinous integument of the 

 gaster had prevented penetration, so that the internal organs were 

 considerably decomposed. In many of the workers, of which more 

 than 20, belonging to three colonies, were dissected, no ovaries 

 could be detected. In one, however, two ovarioles were clearly 

 seen, each of the type figured by Miss Holliday (1903, Fig.Ab, p. 

 295) for the ergatoid queen of Lohopelta elongata,i.e. with a large 

 number of very small ova separated by clusters of nurse-cells. 

 Such undeveloped ovaries were probably present in all the speci- 

 mens but could not be detected on account of defective preser- 

 vation. This may also explain our inability to find a sperma- 

 theca in any of these individuals. Fortunately the mating 

 worker was in a somewhat better state of preservation. The 

 ovaries were found very far forward, in the large first gastric 

 segment and applied to the sides of the crop. There were five 

 ovarioles in each ovary and the lowermost egg in each ovariole 

 was fully developed and of an elongate-oblong shape, as in some 

 other Ponerinse (Pachycondyla, Lobopelta). The vagina and a 

 large spermatheca attached to its dorsal wall were filled almost to 

 bursting with compact masses of spermatozoa. 



For some time evidence has been accumulating to show that 

 Diacamma is not the only ant genus in which the winged queen has 

 been lost and her function in the colony usurped by a fertile 

 worker. The senior author, in the paper aboA^e mentioned (19 lob, 

 p. 337), called attention to the fact that winged females do not 

 exist in the Ponerine genus Rhytidoponera, which is represented 

 by a number of species in the Australian and Papuan Regions. 

 The same condition very probably obtains also in the South 

 African Streblognathus and Ophthalmopone and in the Neotro- 

 pical Dinoponera, all genera belonging to the same subtribe as 

 Diacamma (Pachycondylini). He also stated in his monograph 

 of the Australian honey-ants of the Dolichoderine genus Lepto- 

 myrmex (1915a,p. 260) that true queens are in all probability absent 



