CONSTITUTION AND DEVELOPMENT OF TERMITES. 267 
ages. This deviation may lead to the formation of 
substitute royal forms, or of soldiers, after passage 
through the respective larval stages. The soldier 
larva may originate by modification of examples with 
from twelve to seventeen antennal joints; and the 
larva of the royal substitute forms by modification 
of examples with from fourteen to nineteen antennal 
joints. Perfect insects which are still white may 
also become substitute forms. 
I can confirm the fact discovered by Lespés' in Termes, 
aud by Fritz Miller?in Calotermes, that the caste of soldiers 
is composed of examples of both sexes. 
A minute description of all the forms in the different stages 
of development would be of little interest, and I shall therefore 
confine myself to a few points which have a special bearing on 
the problems I have undertaken to solve. 
Beginning with the sense-organs: 
(1) All trace of eyes is wanting in newly hatched larvee. 
The soldiers possess compound eyes, unpigmented and not 
prominent. The time of their appearance has not been de- 
termined; they are present in a rudimentary condition in 
larve of 3—4 mm. in length, with twelve antennal joints—the 
third glabrous, but they are not clearly distinguishable except 
in sections. Ata later period they are evidently faceted, but 
remain destitute of pigment. The compound eyes acquire 
pigment, as previously mentioned, in nymphs about to become 
imagos and in most examples selected for the dignity of sub- 
stitute kings or queens. In the perfect insect the eyes become 
more prominent and abundantly pigmented, and between them 
is developed an ocellus devoid of any trace of pigment, which 
I therefore regard as rudimentary. 
(2) Sensory hairs (Tastborste), characterised by their 
shortness and their connection with the nervous system, are 
very abundant over the antenne and the whole of the mouth 
1 «Ann. Sci. Nat.’ (4), v, p. 244. 
? (Jen. Zeitschr.,’ vii, pp. 333—340. ] 
