38 THE ARGEXTIXE AXT. 
LIFE HISTORY 
THE EGG. 
(PI. IV, A.) 
The egg is elliptical, pearly white, lustrous, without markings, and _ 
the membrane is extremely thin and delicate. The surface is some- 
what mucilaginous, so that when eggs come in contact they adhere 
to each other. This enables the workers to handle them en masse and 
also permits of their being deposited upon the walls or ceilings of the 
ants' habitations. 
The average size is 0.3 mm. long by 0.2 mm. wide. The largest egg 
encountered while measuring a series was 0.34 mm. long by 0.24 mm . 
wide, and the smallest 0.27 mm. by 0.1S7 mm. 
As time for hatching approaches the luster fades and the surface 
takes on a dull appearance. This is not sufficiently pronounced and 
uniform, however, to be taken as a safe guide to immediate hatching. 
When the embryo takes on the larval shape the membrane not infre- 
quently adapts itself in a way to the general contour of the inclosed 
embryo, thus making it very difficult to distinguish between the eggs 
and the newly-hatched larvae. 
In the large Janet style cages the workers seem to take elaborate care 
of the eggs in order to secure for them just the requisite amount of 
humidity. Frequently they will be shifted several times in the course 
of the day, first being stored in one corner, then moved to the center 
of the compartment, afterwards carried to another compartment, and 
perhaps finally stuck to the glass ceiling. Sometimes the eggs are 
separated from the larvae and pupae; at other times they will be stored 
together in apparently hopeless confusion. 
The care of the eggs by tne workers seems essential to complete 
embryonic development. Eggs deposited in test tubes by isolated 
queens have gone through a portion of the embryonic development, 
but we have not been successful in getting them to hatch. This may 
be due in part to the ease with which the delicate embryos are injured 
in handling and to the fact that when placed on glass the condensing 
moisture may retard or stop development. 
The queen appears to act merely as an egg-producing maclvine, and 
once the egg has been deposited she pays no further attention to it. 
The act of oviposition has been observed several times and does not 
occupy more than a few seconds of time. An attendant ant appears 
to be anxiously watching for the appearance of the egg, and it is 
immediately picked up and rushed off to the nearest ''egg pile/' 
sometimes before it has time to touch the floor of the nest. 
Attempts to get fertilized queens, unattended by workers, to 
deposit eggs and rear the resulting larvae to maturity have been 
unsuccessful. Such queens stop laying a few days after their isola- 
tion and seemingly pay no attention to what few eggs they do deposit. 
