ANATOMY AND PHYSIOLOGY. 
Moll 29 
that their function is probably merely digestive. The liver is formed of 
two lobes united on the ventral face of the stomach ; the salivary glands 
are in the form of arborescent tubes, and in the mouth there is a pair of 
small bodies, which seem to represent two others. The organ of Bojanus 
consists of two unequal lobes, the right being the larger. It opens in 
common with the genital glands at the right side of the anus. The 
female reproductive gland is in the form of a crescent; its upper surface 
is intimately connected with the liver, and rests laterally on the foot 
and epipodium. Fissurella reticulata deposits its eggs on flat stones in 
a single layer, by the aid of undulatory movements of the foot. 
Boutan (47). 
Bourquelot (43) has examined the digestion of Cephalopoda , and finds 
that the liver and the organ called £t pancreas” are digestive, but not the 
salivary glands, spiral intestine, or intestinal canal. The liver secretion 
contains diastase, trypsin, and pepsin ; the pancreas diastase, identical 
with that of the higher animals and of malt; the trypsin is used in the 
digestion of proteids, which resembles in all points the pancreatic diges¬ 
tion of higher animals. The process takes place in the stomach, and the 
matters do not pass into the caecum owing to the presence of a valve. 
That the liver contains no pepsin cannot be regarded as decided, 
although it is said that this and trypsin cannot exist in the same fluid. , 
Fats are emulsionised in the stomach. The liver contains glycogen, 
mucin, leucin, and tyrosin, but no bile acids nor bile salts. Griffiths 
(148) has found -leucin, tyrosin, and a diastatic ferment in the liver of 
Sepia , and also, though not constantly, “ albumen in pseudo-crystalline 
aggregations.” See also * Chem. News, xlviii. p. 37, li. p. 241 ; J. Chem. 
Soc. xlvi. p. 94, 1884 ; and abstr. J. R. Micr. Soc. (2) v. p. 622. 
Dybowski (115) has investigated the masticatory apparatus of Palu- 
dina vivipara and Limnceus stag nails. The lingual cartilages are two, 
which overlap by a thin margin in the middle line ; their tissue is entirely 
cellular, with no intercellular matrix, and comparable to the embryonic 
cartilage of higher animals. The jaws consist of : (1) muscles, mostly 
longitudinal; (2) cellular tissue, supporting the jaw proper ; and (3) the 
epithelium, which secretes a thick cuticle and a prismatic rod-layer, the 
true masticatory portion. The differences between the two forms investi¬ 
gated are indicated. 
The same author (112) has studied the dentition of Limnceus stagnalis 
var. vulgaris , which he considers a fifth type of fresh-water Pulmonata. 
The formula is 1-19-15-15 ; there are from 100 to 102 rows. He finds 
also that in Planorbis mcirginatus the median and outer teeth resemble 
those of Choanomphalus rather than of the Limnceidce (114b) ; and fur¬ 
ther describes the buccal organs of Physa fontinalis (113). 
Rossler (315) has investigated the formation of the radula in various 
groups of Mollusks. The radula-sheath is a diverticulum of the buccal 
epithelium. The evaginated epithelium is in the form of a groove, filled 
with a plug of connective tissue. At the extreme end of the diverti¬ 
culum is a group of specially developed epithelial cells, which secrete the 
teeth and the basement membrane. These are either a few large cells, 
with large nucleus and clear protoplasm ( Pulmonata , Opisthobranchiata ), 
