94 
Psyche 
[March 
Thus, summing the output of the two colonies together over the 
period of approximately a year after observation was begun, those 
fragments containing a brood queen produced a total of 255 pupae 
which were identified as workers, 6 identifiably callow workers, and 
no males. Those fragments of both colonies containing workers only 
brought to maturity a total of 240 pupae identified as males and 26 
identified young adult males, a total of 266 males. In Colony No. 2 B, 
three callow workers were also brought to maturity at the time of an 
early count. It seems a safe assumption, however, that these indi- 
viduals represented the final, delayed residual of queen-laid brood 
“inherited” from the partitioning of the colony some three months 
earlier. 
Thus it seems very clear that in R. purpurea worker brood is 
entirely derived from the fertilized brood female in typical Formicid 
fashion. Workers, however, can produce and rear a prolific male 
brood, at least in the absence of the parent female. Whether the male 
brood which typically appears seasonally in large numbers in normal 
wild colonies is queen- or worker-derived, or both, is an interesting 
and important question for future investigation. It applies with 
equal cogency, of course, to the vast range of “normal” Formicid 
species. 
SOURCE OF WORKER AND MALE BROOD IN SPECIES WHERE 
NORMAL QUEENS ARE RARE OR ABSENT 
Rhytidoponera metallica 
Between December 23 and 25, 1963, a number of vigorous colonies 
of Rhytidoponera metallica were collected at various points in the 
Blackall Range in Queensland, Australia, some sixty miles north and 
thirty miles east of Brisbane. No perfect females were found. These 
colonies were housed and maintained in modified glass Lubbock nests 
of the same design as those used for R. purpurea. After a preliminary 
incubation period of approximately six months, to allow brood resident 
in the colonies at the time of capture to mature, samples of cocoons 
were withdrawn at intervals, opened, and the contained pupae scored 
for sex and caste. Callow workers that were obviously fresh-hatched 
were scored at the same time. The result are given in the table below 
(p. 95 )- 
Thus a total of 644 worker pupae or young adults were produced 
in the five “queenless” colonies of R. metallica over a period of little 
more than six months, and only 1 1 males. It seems clear that worker 
production by morphological workers is a normal feature of this 
species. 
