502 TRANSACTIONS LIVE RPOO!S BIOLOGICAL SOCIETY. 
duct,” which runs forward alongside the oesophagus to 
the buccal mass (fig. 17). 
The sub-lingual gland is oval, and _ thickened 
posteriorly (Pl. IV, fig. 23, s./.g.). In those Cephalopods 
whose development has been studied, it arises as an 
infolding of the ventral wall of the pharynx of the 
embryo, below and anterior to the sub-radular organ. 
This infolded region then gives rise to many tubular 
caeca, each of which opens independently by a minute 
opening into the buccal cavity. These tubules, connected 
together by indifferent tissue, thus form the compact 
sub-lingual gland. The three salivary glands all consist 
of glandular secretory tubules, embedded in a stroma of 
connective tissue (Pl. V, figs. 34 and 35, Tw., Sir.). 
These tubules are closely adpressed in the anterior glands, 
but much further apart in the posterior glands, and 
branch dichotomously here (figs. 35 and 34). The 
secretory cells of the three glands are all similar, and are 
columnar with a basal nucleus. ‘The secretion forms in 
globules in the anterior portion of the cell, and then falls 
into the lumen of the tubule (Pl. V, fig. 36). The 
secretion of these glands is a kind of mucus only, and 
contains no ferment whatever (Frédéricgq and Bourquelot). 
The venous blood, collecting in the sinuses occurring in 
the stroma of connective tissue which binds the secretory 
tubules together, passes out directly into the perivisceral 
venous sinus. 
Stomach.—This is a very muscular grinding organ, 
reminding one of the gizzard of a bird. Its ventral and 
dorsal walls are thickened anteriorly into grinding pads. 
These are thick and stout, and ridged internally. The 
posterior and lateral walls are, however, thinner. The 
oesophagus opens into the stomach at its right anterior 
angle, and the origin of the spiral caecum and. intestine 
