12 
Fig. 42. Longitudinal section through a part of the sublingual nerve-ring. 
cc. the accumulation of nerve-cells forming the sublingual gang- 
lion. 
sl. the sublingual connective. 
else » commissure. 
nn‘. nerves to the tongue and radular apparatus. 
Fig. 45. Longitudinal section through the pedal nerve-stem close to the post- 
erior extremity of the body. 
f. fibrous centre with a superficial sheath of nerve-cells. 
s. nuclei of the neurilem. 
Fig. 44. Transverse section through a pedal nerve-stem at the point from which 
a pedal commissure originates. 
PN. the pedal nerve, internally fibrous, exteriorly cellular. 
cm. part of the commissure from which spring 
n,n!,n?. nerves towards the foot and foot-gland. 
s. nuclei of the neurilem. 
Fig. 45. Transverse section through the wall of the intestine. 
e. the cellular epithelium resting upon a very thin membrane 
of connective tissue. 
s. the secretion of these cells, protruding into the intestinal 
cavity. 
Fig. 46. Diagrammatic view of the glands and ducts in the posterior extre- 
mity of the animal. This figure is reconstructed by the aid of 
an uninterrupted series of sections. 
hg’. right | eiliated duct conveying the genital products out of 
hg. left ) the hermaphrodite gland into 
P. the pericardium. 
dd’. the paired eiliated ducts leading from the pericardial cavity 
into the tubes 
AR A’R’, provided with a partial muscular constrietion in me. 
EE‘. glandular structures superposed upon those tubes. 
00’. common opening of the ducts dd’ and the glands EE’ into 
a ciliated vestibulum corresponding with AA’ (ef. fig. 52). 
Q. the posterior portion where the tubes RR’ are fused into one. 
q. opening of this tube into the anal cavity. 
xy. imaginary line through which the section of fig. 32 was 
taken ; 
vw. the same for fig. 39; 
tur. > » » 20388 
Fig. 47. Diagrammatie view of the whole genital apparatus viewed from below. 
