428 
AUSTRALIAN TERMITIDjE, 
there is nothing but coarse gravel of which the large nests of the 
common reddish-brown ant (Iridomyrmex purpureus), also common 
in this district, and which construct large underground chambers, 
are wholly composed. 
The foundation of the termite nest rests upon the surface and 
is complete in itself, and if you cut one round the base and then 
insert a lever under the edge it is very easy to overturn the whole 
nest; underneath the ground is smooth and hard with only a few 
insignificant passages leading below. 
Under normal conditions the enveloping earthy walls contain 
very few insects, though there are always a few winding passages 
running upwards and traversing them at irregular intervals; upon 
the removal of this outer wall you expose a pyriform mass of 
roughly granulated woody substance in contact with the covering 
wall at the base, but gradually receding from it toward the apex, 
where a space of several inches divides them. The summit of the 
mass on the outside can be easily broken off in lumps, but as you 
cut into it it becomes harder and more solid; galleries run all 
round these masses and form irregular mazes of roadways lower 
down, giving the termites access to all parts of the structure. 
This portion of the nest (all the inner portion enclosed in the 
earthy dome) is organic and is chiefly composed of triturated wood 
which has at one time been gnawed up by the termites and then 
evacuated by them; each of these granulated lumps shows a dis- 
tinctly foliated structure as if it had been formed in thin coats; 
no doubt when the fresh wood supplies are used up, this part of 
the nest is again eaten. 
Immediately in the centre of the nest, about six inches above 
the base, is a rounded mass about as big as a man's head, formed 
of very thin layers of woody matter like brown paper, full of fine 
chambers and passages, the layers very close together and folding 
round each other towards the centre. This is the "nursery" of the 
termitarium, and generally contains thousands or rather millions 
of delicate white larva?, many of them no larger than a pin's head. 
I have never seen any signs of fungi growing in these nurseries as 
mentioned by many writers, but the walls have a curious mottled 
