THE HEPATIC CELLS OF THE EARTH-WORM. 55 
layer, but lies free (Pl. VII., fig. 1). This arrangement 
obtains for about three quarters of the length of the 
intestine. In the last quarter, no distinct lateral masses 
are to be seen, the cells being chiefly aggregated round 
_ the dorsal blood vessel. 
The cells round the dorsal blood vessel above and in 
front of the gizzard are small and few in number. 
When a piece of the alimentary canal is teased in water, 
or weak glycerine, the cells are seen to consist of an 
elongated oval body (figs. 4 and 5), from which proceeds 
a long process, which in its course usually shews an 
ampulla-like swelling. The process, after passing between 
the muscular fibres surrounding the intestine, becomes 
lost among the young cells lying between the bases of the 
columnar ciliated epithelial cells lining the intestinal wall 
(figs. 2 and 3). The body of the unicellular gland, the 
duct-like projection and its ampulla, when examined 
under Gundlach’s 1-12th inch objective, are found to be 
full of minute yellowish rounded granules of variable size, 
perfectly homogeneous in structure (fig. 6). 
The cells are much longer on the dorsal surface than on 
the ventral. They are especially long in the typhlosole. 
With regard to their function, despite the doubts 
thrown on their hepatic nature, we are inclined to think 
that the balance of evidence leads to that view rather than 
to any other which has been advanced. 
In the first place, their distribution at once suggests 
digestive or absorptive duty. 
Again, the contents of the intestine, as stated by 
Darwin,* are distinctly acid, although the pharynx is 
alkaline and the gizzard very slightly acid. We found 
the reaction of these cells and of the outer surface of the 
* Vegetable Mould and Harth Worms. 1883, p. 52. 
