414 ANATOMICAL AND PATHOLOGICAL OBSERVATIONS. 



renders each cell prominent and turgid, and is the cause of its 

 dark colour. 



The dilated terminal extremities of the ducts in the liver 

 of Helix aspersa (Mliller) contain a mass of cells. If one of 

 these cells be isolated and examined, it presents a nucleus 

 consisting of one or more cells. Between the nucleus and the 

 wall of the containing cell is a fluid of an amber tint, and 

 floating in this fluid are a few oil-globules. This fluid differs 

 in no respect from the bile, as found in the ducts of the 

 gland. 



If a portion of the ramified glandular organ which opens 

 into the fundus of the stomach of Uraster rubens (Agassiz) be 

 examined, its internal surface is found to be lined with cells ; 

 between the nucleus of each of which and the wall of the cell 

 itself a dark-brown fluid is situated. The organ secretes a 

 fluid, supposed to be of the nature of bile. 



The dark-brown ramified cseca of the same animal exhibit 

 on their internal surfaces an arrangement of nucleated cells, 

 the cavities of which contain a brown fluid. These caeca are 

 also supposed to perform, or to assist in the performance of, 

 the function of the liver. 



The liver of Modiola vulgaris (Fleming) contains masses of 

 spherical cells. Between the nucleus and the wall of each of 

 these cells a light-brown fluid is situated, bearing a close re- 

 semblance to the bile in the gastro-hepatic pouches. 



The nucleated cells which are arranged around the gastro- 

 hepatic pouches of the Pecten opercularis are irregular in 

 shape, and distended with a fluid resembling the bile. 



The hepatic organ, which is situated in the loop of 

 intestine of Pirena prunum (Fleming), consists of a mass of 

 nucleated cells. These cells are collected in groups, in the 

 interior of larger cells or vesicles. These nucleated cells are 

 filled with a light-brown bilious fluid. 



The hepatic organ, situated in the midst of the reproductive 



