1887.] NATURAL SCIENCES OF PHILADELPHIA. 303 



on each side lapi:)ing over the stomach and intestine (fig. 10 cor.). 

 The cells and their arrangement in these coeca are of an entirely 

 different character from those of the oesophagus, stomach or intestine. 

 A transverse section shows a series of very jirominent, coarsely 

 granular, pyramidal cells, containing in the lower third a round 

 nucleus and several, usually three, nucleoli. They are separated 

 from one another by lighter, finely granular spaces, which when 

 viewed from the surface of the coecum (fig. 11.) j^resent a retic- 

 ulated appearance. 



Whether this is due to the presence of small polygonal cells sep- 

 arating and surrounding the large glandular cells, or whether it is 

 a mesh work of threads, formed from the secretion of these cells 

 and connecting them, as in the livers of some molluscs, I can not 

 be positive; I can not, however, detect any nuclei in the cell-like 

 spaces. 



Huxley^ described but one coecal appendage in Salpa, and called 

 it the stomach, into which, according to his description, opened the 

 duct from the net-work of anastamosing tubules which ramify over 

 the visceral nucleus. In the form which I have examined there 

 are present two coecal appendages (fig. 10) as single sections plainly 

 show and as I have learned positively by a model of the visceral 

 nucleus constructed according to Born's "Platten-Modillir" method.^ 

 Seeliger in his paper, referred to further on, also mentions and fig- 

 ures but one coecum. I can only account for the disagreement be- 

 tween the observations of Huxley and Seeliger on the one hand 

 and my own on the other, by the supposition that the number of 

 coeca varies in different species. I shall take advantage of the earl- 

 iest opportunity, however, to examine the visceral nuclei of all spe- 

 cies of Salpse. 



My observation agrees with those recently made by Seeliger in 

 confirming H. Miiller's statement that no food is ever found in these 

 coecal appendages, but their lumen is often filled with a structure- 

 less product of secretion. Opening as they do at the anterior end 

 of the stomach they are evidently of some material use in digestion, 

 and from the arrangement and structure of their walls I am of the 

 opinion that they function as hepatic organs, as was first proposed 



il. c. p. 571. 



^ Aichiv. f. niikroscop. Anat. xxii, p. 684, 1883. Amer. Naturalist, 

 April 1884. 



