1950] 
Haskins and Haskins — Brachyponera lutea 
3 
to dangers from predators from which the female of Lasius or 
Camponotus is permanently protected as soon as its first cell 
is constructed. Finally, even if the young queen of Myrmecia 
succeeds in overcoming the numerous environmental hazards of 
drought or excessive moisture, of scarcity of food-sources, and 
of reptilian, avian, and mammalian predators during the diffi- 
cult days of colony foundation, it is quite likely to become lost 
or otherwise permanently separated from its nest and its first 
brood in the course of its extensive wanderings. 
Before this advantageous specialization can have taken place 
in the course of Formieid evolution, however, several con- 
comitant physiological specializations must have occurred in 
whole or in part, and have been at least partially perfected. One 
of them is the ability of the individual to regurgitate ingluvial 
food for the larvae, thus precluding the necessity of supply- 
ing the larvae entirely with solid nourishment which must be 
brought in from outside. This power of regurgitation seems to 
be wholly lacking in both the Myrmeciini and the Amblyoponini. 
A second specialization which, while not essential to the develop- 
ment of the claustral method of colony foundation, is exceed- 
ingly helpful to it, is the facult}^ of breakdown of wing-muscle 
tissue to form a reserve of nutriment for the female. Work is in 
progress to determine whether there is any indication of such 
a development in Myrmecia or in Amblyopone. If present at all, 
it is certainly not nearly so conspicuous as among the higher 
ants. Third, it must have been essential, before the claustral 
method of colony foundation could be fully established, that a 
considerable difference of size should have been developed be- 
tween the queen and the worker forms of a given species, so 
that several of the latter, pupating prematurely, could be sus- 
tained from the much greater bulk of the queen, with its spe- 
cialized reserve of fat-body and perhaps of transformed wing- 
muscle tissues. 
It is clear that none of these specializations occurred sud- 
denly in evolution, and that they must all have been closely 
interrelated. Concomitantly, it would be expected that the devel- 
opment of the claustral mode of colony foundation would have 
occurred gradually, as these physiological specializations pro- 
gressed, manifesting itself as a growing reliance of the queen 
on the sustaining powers of her own tissues, and an increasing 
