1922] The Mating of Diacamma 205 



a nest of D. rugosum subsp. vagans var. indicum and took to 

 be queens, but in 1903 he was compelled to admit that what he 

 had seen was ''only a large male." The perusal of his description, 

 however, shows that he could not have seen even males of 

 Diacamma, for they were colored like the worker and sculptured, 

 whereas the male of vagans, of which we have numerous speci- 

 mens, is smooth and yellow. There can be no doubt that he 

 saw males of a very different Ponerine ant, namely Odontoponera 

 transversa Smith, and that he must have been mistaken in regard 

 to their belonging with the vagans workers among which he 

 found them. 



These failures led Emery (1911, p. 64 7iota) to conclude that 

 "we must suppose that the female Diacannna resembles the 

 worker so closely as to be confused with it." In 1914 the senior 

 author studied D. australe at Cairns and Kuranda in Northern 

 Queensland and, after alluding to the failure of previous ob- 

 servers to find the missing phase, made the following statement 

 (1915b, p. 335) : "In excavating the nests of australe, therefore, 

 I scrutinized the ants verj^ closely in the hope of finding the 

 unknown female, but in vain. Though I searched dozens of 

 nests, I saw nothing resembling a winged female or even a 

 worker with conspicuously enlarged gaster. I found plenty of 

 larvae and pupae and in some of the nests during late October a 

 number of males. These are bright reddish yellow, with con- 

 spicuously long antennae and quite unlike the bronzy black 

 workers. As I failed to find any differentiated queen and as all 

 the pupae were of the same size, I feel confident that in Diacamma 

 the egg-laying function must be usurped bj^ one or more fertile 

 workers during the breeding season." 



That the assumptions of Emery and the senior author were 

 well founded has now been demonstrated by the junior author's 

 observations on D. rugosum subsp. geometricum Smith in the 

 Phillippines. During a sojourn of six years at Dumagucto in 

 Negros Oriental he found D. geometricum to be a conunon ant 

 from sea-level to about 3000 ft., living in open "cogon" or 

 shrubby places along the edges of forests, where the vegetation is 

 only three or four meters high. Here it nests under the bark of 



