270 B. GRASSI AND A. SANDIAS. 
The broad fact remains that individuals exist with from 
thirteen to seventeen antennal joints, with either the third or 
fourth (fig. 20) or both joints glabrous, or without a single 
glabrous joint. 
How are the new joints formed? I regard it as certain 
that the 13th arises by unequal division of the 3rd, at the 
base of which it appears as a bud. The 15th and 17th appear 
to arise from the 4th, and the remainder like the 13th (Pl. 16, 
figs. 20—22). But closer study is necessary before arriving 
at a conclusion. 
It is of fundamental importance to notice that the new 
joints do not take origin from a zone of embryonic (undiffer- 
entiated) tissue, but from already differentiated structures 
(hy podermis, nerves, &c.). 
Calotermes moults periodically, and it is quite untrue 
that the number of antennal joints increases coincidently with 
the moult. It is more probable that the latter takes place 
after the process of joint formation, and in this we may per- 
haps find the explanation of the just related facts respecting 
the loss of antennal hairs. 
The number of ecdyses cannot be specified ; I have found 
examples of all sizes in process of moulting, and can go no 
further than to fix it at not less than five. The adults and 
soldiers do not moult ; and the latter are derived from soldier 
larve by an ecdysis, so that while the exuvie are larval, the 
new instar is that of a fully-developed soldier. 
As with other insects, the operation is accomplished by 
means of an anterior medio-dorsal fissure, through which are 
drawn out first the head and thorax, and lastly the abdomen 
(Pl. 16, fig. 15). In rare cases an example has been seen to 
be assisted in the operation by his comrades. 
Two ecdyses merit special attention. The first is that 
undergone by the nymph, furnished with wings apparently 
small in size (really of full dimensions and elaborately folded 
up under the old ensheathing cuticle), and with genital appen- 
dices ; from this it emerges with wings of full amplitude, and 
