LETTERS ON ENTOMOLOGY. 83 
hiss from all the labourers, and appears to be a 
signal for despatch ; for every time it is heard, 
they are seen to redouble their pace with increased 
diligence. If you renew the attack, the same 
scene will be repeated; the labourers will dis- 
appear, and the soldiers rush forth as before; 
and when all is quiet, the workers resume their 
task, but never attempt to fight. The termites, 
however, do not always go under covered-ways. 
There is a larger species, which Mr. Smeathman 
calls the marching termes. He was once passing 
through a thick forest, when, on a sudden, a loud 
hiss like that of serpents struck him with alarm : 
the next step produced a repetition of the sound, 
which he then discovered to be that of the white 
ants ; yet he was surprised at seeing none of 
their hills or covered- ways. Following the noise, 
to his great astonishment and delight, he saw an 
army of those creatures emerging from a hole 
in the ground ; their number was prodigious, and 
they marched with the utmost celerity. When 
they had proceeded about a yard, they divided 
into two columns, chiefly composed of labourers 
about fifteen abreast, following each other in 
close order, and going straight forward. Here 
and there was seen a soldier, carrying his vast 
head with apparent difficulty, and looking like 
