92 
For some time I had noticed ants come out of the nest carrying 
what seemed to be the corpse of ants in their mandibles. I easually 
noted that they dropped their burdens and returned to the nest. 
Later on, I discovered that these burdens were /7ve ants, and that 
when deposited, both parties plodded away in opposite directions 
without showing the shghtest trace of emotion. Other observers who 
have witnessed similar occurrences have thought them to be a kind 
of play; but what I saw was much too solemn to be ealled a frolic. I 
would suggest that the ants carried out were ‘‘callows’’, that is ants 
newly emerged from the chrysalis, and that after being allowed to 
harden their shells for some days in the shelter of the nest they were 
thus formally introduced to the outside world as a hint that they might 
now undertake the regular work of the nest. 
Professor Wheeler has established the fact that it is only ‘‘eal- 
lows’? which are capable of becoming repletes. Once an ant gets 
thoroughly matured and hardened it appears to lose the elasticity re- 
quired in order to allow of the enormous distention of the erop whieh 
characterizes the replete. An ant in process of becoming distended 
Fig. 4. Five replete majors of Myrmecocystus mexicanus mojave posed on a string. 
to the proportions of a replete can never be confounded with a re- 
plete who has fed away her store and is slowly collapsing to her 
normal condition. In the former case the gaster is tense and more 
or less spherical (Fig 4). in the latter the skin is corrugated into folds 
and the segments stand out as ridges. 
MYRMECOCYSTUS MEXICANUS 
These ants have never been found in the United States until 1910, 
and our discovery of a nest on Point Loma was the third reported 
occurrence of this species in the year. 
