22 ORIGIN OF THE SOLDIERS. 
Lund! pointed out that there were two different kinds 
of workers, but Bates has since shown that there are 
in this species no less than five classes of individuals, 
namely: J. Males. 2. Queens. 3. Small ordinary 
workers (Pl. III. fig. 2). 4. Large workers (Pl. IE. 
fig. 1), with very large hairy heads. 5. Large workers, 
with large polished heads. Bates never saw either of 
these two last’ kinds do any work at all, and was not 
able to satisfy himself as to their functions. They 
have also been called soldiers, but this is obviously a 
misnomer—at least, they are said never to fight. Bates 
suggests? that they may ‘ serve, in some sort, as passive 
instruments of protection to the real workers. Their 
enormously large, hard, and indestructible heads may 
be of use in protecting them against the attacks of 
insectivorous animals. They would be, on this view, a 
kind of piéces de resistance, serving as a foil against 
onslaughts made on the main body of workers.’ 
This does not, I confess, appear to me a probable 
explanation of the fact, and on the whole it seems that 
the true function of these large-headed forms is not 
yet satisfactorily explained. 
The question then arises whether these different 
kinds of workers are produced from different eggs. 
I am disposed to concur with Westwood in the 
opinion’ ‘that the inhabitants of the nest have the 
instinct so to modify the circumstances producing this 
1 Ann. des Sct. Nat. 1831, p. 122. ® Loe. cit. p. 31. 
* Modern Classification of Insects, vol. ii. p. 225. 
