THE HEPATIC CELLS OF THE EARTH-WORM. 53 
is unknown. They are elongated granular cells of large 
size, and arranged generally radially to the surface of 
the intestine. They are very abundant in the cavity of 
the typhlosole, which they almost completely fill.’’ 
Lloyd Morgan* says, ‘‘ Surrounding the intestine, 
especially at its anterior end, is a yellowish- brown, 
easily ruptured tissue, which is in close connection with 
the blood vessels. Similar tissue may accompany the 
dorsal vessel above the cesophagus. It has been described 
as hepatic, and as producing a digestive secretion. It 
nowhere communicates, however, with the interior of 
the canal, and its close connection with the blood 
vessels lends support to the view that it is vasifactive— 
concerned in the production of some constituent of the 
red fluid of the blood vessels.” 
Howes? affirms that ‘‘the brownish-yellow tissue, usually 
termed liver, has no direct connection with the lumen 
of the alimentary canal. It is always associated very 
largely with the blood vessels, and is in all probability a 
direct derivative of their walls. It appears to be active in 
the production of some constituent of the blood, similarly 
to that tissue described by Lankester in the leeches as 
vasifactive.” 
No very definite account or good figures are to be found 
of these cells in any of the papers or text books above 
quoted, so that it may not be out of place to summarise 
the main features of this functionally doubtful tissue. 
The cellular layer is distinctly visible, through the 
body wall, when the animal is stretched and under water, 
as a yellow-brown streak, particularly at the posterior end 
of the body. On dissection, generally speaking, the yellow 
cellular investment extends from the first ‘‘ pseudoheart”’ 
* Animal Biology. 1887, p. 283. 
+ Atlas of Biology. 1885, p. 49. 
