330 
Observations on Termites 
fate of the young on hatching is not predetermined, but depends on the sub- 
sequent treatment they receive at the hands of the workers. According to this 
view any given individual on hatching from the eggs may, in the case of T. 
natalensis for example, develop into any one of five distinct forms or castes, which 
in no way grade into one another, viz. two forms of soldiers, two forms of workers 
and the winged sexual form. It is certainly most difficult to form a conception on 
any theory of heredity as to the means by which hereditary characters could be 
inherited by such a plastic and modifiable organism as the newly hatched young 
of a termite. 
After the first rains the winged sexual forms swarm out of the nest and 
copulate in the air ; they seldom or never appear to return to the parent nest. 
A pair may succeed in founding a new nest, and will ultimately become the queen 
The nest of T. natalensis is slow in growing, and it remains inhabited for many 
years. The same queen and king undoubtedly live for a number of years, and 
in some species (including T. natalensis) it is not known how they are replaced, 
should they die or an accident befall them. 
(2) The Measurements. 
The measurements were made only on what appeared to be adult members 
of the different castes, except in the case of the winged images, when on one 
occasion nymphs with wing-rudiments were measured. An individual was re- 
garded as adult when the exoskeleton of the head was firm and had assumed 
the characteristic yellow or brown colour. This point is, of course, of considerable 
importance as there is no sharply marked metamorphosis among termites. 
In any case, whether of soldiers, workers or winged images, the same dimension 
was chosen for measurement, viz. the maximum breadth of the head {ah in figure 
below). Owing to the varying configuration of the head in the different castes and 
species, this dimension in certain cases passes through the compound lateral eyes ; 
and king. 
