CONSTITUTION AND DEVELOPMENT OF TERMITES. 251 
&c., if in want of them. In short, after a certain time the tube 
will contain a complete little nest, if it did not oxiginally 
do so. However, the insects do not hesitate to bore through 
the cork, and, unless they are watched, one is surprised to find 
some day that they have all made their escape. But fre- 
quently they remain in the tube, even though they have made 
holes putting them into communication with the outer air 
(PL 19, fig. 11). 
Some of these little nests can be kept alive for several 
months, but many die off after a few weeks, though not until 
they have afforded sufficient opportunity for making numerous 
observations through the glass walls by aid of a lens. It is 
desirable to use tubes of various lengths and calibres, because 
certain points are better seen in a wide than in a narrow 
tube. 
In addition to the insects, the tubes are partly filled with 
fragments of wood, which should be neither too dry nor too 
moist. In the former case the insects gradually shrivel, con- 
tract, dry up and die; and in the latter case there is a deposit 
of water vapour on the inner walls, and they are evidently 
killed by over-dampness. Death ensues more or less rapidly 
according to the amount of water deposited, and is sometimes 
almost as sudden as if the insects were suffocated or chloro- 
formed. Slow death due to over-dampness may be accom- 
panied by distinct cedema or reddish discoloration of the 
darkening of the chitin concomitantly with the maturation of the gonads after 
the last ecdysis. They leave the nest by “swarming.” The neoteinic 
royal forms undergo a premature maturation of the gonads whilst in a late 
arval or nymphal instar, or that of an immature and pallid imago. This 
maturation is accompanied by an arrest of development of other parts of the 
body; the chitin does not darken normally, and the wings do not grow 
further. They do not leave the nest. The latter class is further subdivided 
into complementary and substitute royal forms. Complementary 
forms are not found in Calotermes, but are normal components of the Termes 
nest, in which they are the only reproductive individuals. Substitute 
forms are developed to supply the loss of the true royal forms in Calo- 
termes, or the complementary royal forms in Termes. ‘The three varieties 
of royal examples all comprise kings and queens,—that is, individuals of 
each sex. ] 
