2 bo Psyche [June 
it prefers open, partially xerophytic woodland habitats, but ranges 
much further, to South Australia and probably New South Wales 
and Victoria as well. It is an unusually hardy species and its colonies 
can be maintained in laboratory culture for many years. The pri- 
mary reason for choosing it for this investigation, however, was that, 
in the populations from which nests were selected for both field and 
laboratory work, even mature colonies are typically quite small. 1 
This and other characteristics suggest that the species is one of the 
socially less-evolved members of the genus and thus lend particular 
interest both to the reactions of its workers to necrophoric substances 
and to pheromones of higher ants. 
Laboratory Tests 
Reactions of workers of Myrmecia vindex to Oleic Acid 
A portion of a colony of M. vindex consisting of approximately 
30 workers, 20 cocoons, and 25 larvae, collected at Kings Park, 
Perth, West Australia, on December 28, 1961, and long established 
in the laboratory in an earth-containing Lubbock type glass nest of 
dimensions 7" X 12" and Y\ r in depth, was set up in a foraging 
arena consisting of a rectangular plastic box, 48" X 24" X 6.5" 
in inside dimensions, to which the ants had free access. The bottom 
of the arena was covered with clean brown paper. 
After the colony had become thoroughly conditioned to the en- 
vironment, piles of brood which had been impregnated with 1 to 2 
drops of various substances were placed on cardboard sheets, 6" X 
8", at some distance from the nest entrance. There was early indi- 
^ounts of four completely excavated apparently mature colonies from 
this population were made in January, 1964, with the following results: 
Colony 1 
21 
typical brood female 
callow subalates (apparent female-worker intermediates) 
211 
workers 
Colony 4 
1 
typical brood female 
176 
workers 
Colony 6 
1 
typical brood female 
187 
workers 
Colony 7 
1 
typical brood female 
149 
workers 
This compares with a population count of a study nest of M. vindex reported 
by Douglas 
and 
McKenna (1970) as follows: 
1 
typical brood female 
38 
alate virgin females 
38 
dealate virgin females 
210 
workers 
224 
males 
