jaws, lifts it up above its
head, so that the centre of gravity of the load is above the ant
itself. It then marches off, down the stem, to the base, over the
ground to the end of the street, and along this to the nest,
travelling at a very uniform speed, and never letting go its load. The
weight thus carried was found, on an average, to be twice that of the
ant; but many were found carrying heavier loads, even as much as ten
times their own weight!

The nests are usually below the surface of the soil, but covered,
wherever necessary, with a thick mass of withered pieces of leaves and
twigs, etc. They may be as much as 1-1/2 metres in diameter. In the
nests of all species examined there is found, filling up the interior,
a curious grey spongy mass, full of chambers, like a coarse sponge, in
which the ants may be seen running about, and in which, here and
there, occur eggs, larvae, and pupae. This is the fungus garden. It is
separated from the roof and lateral walls of the nest by a clear
space. The walls and roof are much thicker in winter than in summer;
one nest examined had a roof 25 cm. thick and wall 40 cm. The garden
consists of two parts, differently coloured, but not very sharply
marked off from each other. The older part is yellowish-red in colour;
the newly-built portions, forming the surface of the garden, are of a
blue-black colour. It is this part which is of the greater importance
to the ants.

The garden is found, on examination, to consist of an immense
conglomeration of small round particles of not more than .5 mm. in
diameter, of a dark green colour when quite fresh, then blue-black,
and finally yellowish-red. They are penetrated by, and enveloped in,
white fungus hyphae, which hold the particles together. These hyphae are
similar throughout the nest.

Strewn thickly upon the surface of the garden are seen round white
bodies about .25 mm. in diameter; they always occur in the nests,
except in the very young portion of the gardens. They consist of
aggregations of peculiar swollen hyphae, and are termed by Moeller the
"Kohl-rabi clumps." The hyphae swell out at the ends into large
spherical thickenings, filled with richly vacuolated protoplasm like
the ordinary hyphae. These clumps of "Kohl-rabi" are only found on the
surface of the garden, and form the principal food of the ants; they
have no doubt reached their present form under the cultivation and
selection of the ants. The fungus was found to be