296 MR GOODSIR ON THE ULTIMATE SECRETING STRUCTURE, 



cis Algirae vasis sanguiferis, 1840, in which he describes, in the kidney of that 

 mollusk, cells, the nuclei of which pass out by the duct of the gland. It does not 

 appear, however, that EEDL had discovered the uric acid within the cell. 



I have now stated all that is known at present of this subject. No one, as 

 far as I am aware, has proved that secretion takes place within the nucleated 

 cell, or has pointed out the intimate nature of the changes which go on in a se- 

 creting organ, during the performance of its function. It is the object of the pre- 

 sent communication to supply this deficiency in physiological science. 



If the membrane, which lines the secreting portion of the internal surface of 

 the ink-bag of Loligo sagittata (LAMAEK) be carefully freed from adhering secre- 

 tion by washing, it will be found to consist almost entirely of nucleated cells, of 

 a dark brown or black colour. These cells are spherical or ovoidal, and measure 

 from 1.000th to 2.000th of an inch in their longer diameters. Their nuclei con- 

 sist of cells, grouped together in a mass. Between these composite nuclei, and 

 the walls of their containing cells, is a fluid of a dark brown colour. This fluid 

 resembles, in every respect, the secretion of the ink-bag itself. It 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 

 (MtJLLER) 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. The cells measure from 1.000th to 2.000th of an inch. 



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 cells measure from 4.000th to 5.000th of an inch. 



The dark brown ramified caeca of the same animal exhibit on their internal 

 surfaces an arrangement of nucleated cells, the cavities of which contain a brown 

 fluid. These cseca 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, 

 measuring about 3.000th inch in diameter. Between the nucleus and the wall of 

 each of these cells, a light brown fluid is situated, bearing a close resemblance to 

 the bile in the gastro-hepatic pouches. 



The nucleated cells, which are arranged around the gastro-hepatic pouches of 

 the Pecten opercularis, are about 2.000th of an inch in diameter, irregular in 

 shape, and distended, with a fluid resembling the bile. 



The hepatic organ, which is situated in the loop of intestine of Pirena Pru- 



