220 
Proceedings of the Rogal Society 
is stated to be constantly nineteen in fully developed females,* and 
it is very unlikely that an immature form should have more, 
though it might have fewer, segments than the adult. 
With respect to the anatomy of the animal, the following points 
resulting from this investigation seem to be most worthy of notice. 
The cuticle is perforated by the usual stigmata, which are seen 
in section to be somewhat of an hour-glass shape, and immediately 
internal to each is situated a spheroidal cell or group of very small 
cells (fig. 3, (i), with a blunt process projecting into the stigma, the 
arrangement very forcibly suggesting that the function of this 
aperture is to evacuate a substance secreted by the cells. 
The sub-cuticular epidermis (fig. 3, V) consists of columnar nucleated 
cells, and in many cases processes can be traced 
passing from these inwards and becoming con- 
nected either with the muscle fibres or with 
the cells forming the parenchyma of the body 
wall. 
The mouth is annular in form and surrounds 
Pice. 3. TmnsversG sec* 
fi'on of a portion of ^ small oval papilla, which is probably capable 
^ the_ body wall : a, pj-otrusion and retraction, seeing that it 
( cuticle; 0 , layer of _ _ _ _ 
epitlielinm ; c, large it is provided with a sphincter muscle, with 
farge^cefi^ muscles placed longitudinally with respect 
the stigmata; (?,trans- to the body, and with a third group passing 
verse muscular fibres; 
/, longitudinal fibres, inwards at right angles to these. 
The oesophagus commences at the posterior side of this papilla, 
and passes inwards and backwards with a double curve, finally 
entering the stomach some distance behind its anterior margin. 
At first its section is crescentic, with the horns directed dorsally. 
It then becomes oval, and still later crescentic again, but with 
the horns directed ventrally. All this portion of the tube is lined 
with chitin continued from the external covering of the body. The 
middle portion of the oesophagus is once more oval in section, and 
has a well-developed coat of muscular fibres. On passing through 
the nerve-ring its lumen becomes stellate in section, and it enters 
a mass of rather large round parenchymatous cells, whose appearance 
suggests that they are secretory in function, though as yet no excre- 
* Bell, Ann. Mag. Nat. Hist, ser. 5, vol. vi. p. 176. 
