CONSTITUTION AND DEVELOPMENT OF TERMITES. 273 
the possession of small cells, of which the nucleus stains 
more intensely than in the other nerve-cells. 
Should a characteristic feature of these organs be sought, 
by way of contrast with those of less intelligent insects, it 
will be found in the abundance of these particular small 
nervous cells. | 
The visceral nervous system is well developed, and resem- 
bles that of Blattidz (fronto-labral commissures ; frontal and 
stomato-gastrie ganglia, &c.). The salivary glands are supplied 
(only ?) by branches from the subcesophageal ganglion, coming 
off from those to the labium or lower lip. 
The ventral ganglionic chain possesses six abdominal ganglia, 
and thus agrees with Lespés’ description; the sixth is very 
large, and is in correspondence with the true seventh and 
eighth abdominal segments. 
At the level of the fourth abdominal ganglion—that is, in 
the true fifth segment—there open numerous unicellular glands 
of unknown function. The retro-cerebral gland, which exists 
in Termes lucifugus,' is absent. 
Certain features of the different castes and larval forms will 
now be described. 
[Newly born examples are semi-transparent and almost pure 
white. If the mouth parts are detached the apex of the 
mandibles and the inner lobe of the maxille can just be seen 
with the microscope to be tinged with yellow, a feature which 
cannot be made out by examining intact specimens even with 
a good lens. After a few days these parts acquire a more or 
less pronounced yellow colour, owing to the thickening of the 
investing cuticle, and at this time a yellow line, caused by the 
approximated tips of the mandibles and maxille, may be 
distinguished at the front of the head even with the naked eye, 
though better with a lens. 
This yellow line appears early in forms which develop a 
large head (soldier larve), and is delayed in those of which the 
head remains small. At the time of its appearance the animal 
1 [Vide Pl. 16, figs. 28—33, and description. ] 
