CASE OF SAECINA VENTEICULI. 361 



predominance of the constituent cells over the outer coat or 

 lorica, in each frustule being four-celled, and in the entire 

 freedom of these from all coloured contents. Of the specific 

 characters of a single species much cannot be said. 

 I define the genus thus : 



SAECINA. Plants coriaceous, transparent, consisting of six- 

 teen or sixty-four four-celled square frustules, arranged 

 parallel to one another in a square transparent matrix. 

 Species 1. SAECINA VENTEICULI, miUi. PL xi. Fig. 13. 

 Frustules 16 ; colour light brown ; transparent matrix 

 very perceptible between the frustules, less so around 

 the edges ; size 800 to 1000 inch. Hab. the human 

 stomach. 



As soon as I had detected the SAECINA, I called upon my 

 friend Dr. George Wilson for an analysis of the fluid. The 

 following is his report : 



tl The liquid sent me for examination was thick and viscid ; 

 by standing, it deposited a large quantity of ropy matter mixed 

 with portions of undigested food, and when filtered through 

 paper it had a pale brownish-yellow colour, and was quite 

 transparent. It still contained much animal matter in 

 solution, becoming opaque and flocculent when boiled, and 

 giving a very copious precipitate with infusion of galls. It 

 also precipitated nitrate of silver densely, and when evaporated 

 to dryness, and exposed to a full red heat in a platina crucible, 

 left an ash containing much chloride of sodium. It had a pecu- 

 liar acid odour, which all who have observed compare to that 

 of sour beer ; it reddened litmus powerfully, and effervesced 

 sharply with alkaline carbonates. These remarks, and all that 

 follow, apply without exception to portions of liquid ejected 

 at various intervals during a period of four weeks. 



" To determine the nature of the acid which existed so 

 abundantly in the ejected matter, a pint of the filtered liquid 

 was distilled in a retort, till nine-tenths of the whole had 



