93 
On November 6th, I dug up a nest in a soil composed of dis- 
integrated shale. They are hardly distinguishable to the casual ob- 
server from the preced- 
ing species, except by a 
slightly darker color. 
There were many 
semi-repletes moving 
oe about the galleries (Fig. 
pee 5), and about eight lay- 
ine females. 
= Gee ‘ aie rie % When opened up, the 
resulting hole was only 
three feet deep and two 
feet in diameter 
Fig. 5. Winged females of Myrmecocystus mexi- dently a new nest. The 
canus. Partially deflated replete majors, males, : 2 : 
and major, minor and minim workers. ] a ying females: in 
evi- 
pleasing contrast to the 
(jueens in a beehive, are very friendly and spend hours with their heads 
together, caressing one another with their antennae. On January 30th, 
1911, I found a solitary female in a little hole in a bank. The excava- 
tion could not have been more than a day or two old. Had she been 
undisturbed, in due time a new colony would have been produced by 
her unaided efforts. 
Shortly after I had established an island nest in a basin and had 
moistened the earth, a minor worker was struck with the idea of 
sinking a shaft. Accordingly she scratched away at the soil, using 
her fore legs just like a terrier. Her energy was so infectious that a 
major joined her, and presently a minim was drawn into the under- 
taking. Ants digging in pure sand are obliged to remove it grain 
by grain, but the slightest admixture of clay permits the formation 
of pellets thus enormously economizing labor. The loose dirt is first 
scraped into a heap under the ant. The gaster is then curved forward 
and downward as in the act of stinging* and the front pair of legs is 
used to pat the earth against the opposing lower surface of the gaster. 
The loose soil granules are thus packed into a solid pellet, which is 
seized in the mandibles and carried out. When digging a gallery 
against the inner wall of a glass tumbler, the digging consists for the 
most part in tugging at the sand grains and detaching them by main 
foree. The gallery is afterwards enlarged to give passage room for 
the females. One of the nests under observation had its entrance 
*N. B. No ant of the Subfamily Camponitinae, to which the genus Myrmecocystus 
belongs, possesses any sting. They have a large poison bag, the contents of which are 
used to spray their enemies and their prey. 
