30 



ąuickly increases, as it spreads over the wider parts of the cavity, to 

 the extent of 8 lines ; then again gradually diminishes, as it ap- 

 proaches the pyloric cavity, to a thickness of lį line at the greater 

 curvature, but, at the constriction separating the two cavities, again 

 increases to 6 lines : along the lesser curvature it never diminishes 

 in thickness beyond 3 lines, the muscular coat at this part being, as 

 in the human stomach, augmented with additional longitudinal fibres. 



" In order to defend the cardia against the pressure of the con- 

 tents of the stomach, when acted upon by this powerful muscular coat, 

 the cesophagus enters the stomach in a valvular manner, and is sur- 

 rounded at its termination by a vast accession of muscular fibres, 

 forming a conical mass upwards of an inch in thickness all round 

 the canal : the outermost of these fibres run longitudinally ; the 

 middle ones decussate each other obliąuely ; the innermost are cir- 

 cular, and form a sphincter around the cardia. The diameter of the 

 canal so surrounded •was 3 lines, the inner surface being gathered 

 up in irregular transverse rūgte; the cellular coat is increased in 

 thickness at its termination, and protrudes the inner membrane into 

 the stomach likę the os iincce of the womb. 



" The inner surface of the stomach was puckered around the 

 cardia, and presented a few small, irregular rugee along the lesser 

 cun'ature and about the orifice leading to the second cavity, but the 

 remainder was tolerably even and smooth. The inner membrane 

 is a thin, soft membrane, 'vvith a finely reticulate surface. To the 

 left of the cardia there projects into the stomach a rounded mam- 

 milloid eminence, whose base is 2 inches in diameter, and whose 

 apex presents an obliąue crescentic orifice about 3 lines in diameter ; 

 on drawing aside the margins of this orifice, I unexpectedlyfound that, 

 instead of its being the outlet of a simple mass of foUicular glands, 

 as would appear from the figures and description in Sir Everard 

 Home's Account of the Anatomy of the Dugong, it led to a Tvide, 

 flattened, \nnding sinus, and that its circumference was formed by the 

 termination of a membrane spirally disposed in about eight or ten 

 turns, and increasing in breadth at each gyration, having both sur- 

 faces covered with the orifices of numerous glandular follicles, and 

 the interspaces fiUed with a cream-like secretion. 'This structure, 

 which adds another peculiarity to the stomach of the Dugong, and 

 one met with in the cacum only in a few other mammaUa, viz. that 

 of having its blind end occupied by a spirai membrane, I have found 

 in all the specimens dissected at the Society ; and in each case the 

 gland was infested by Ascarides, hereafter to be described, which 

 left impressions upon the spirai membrane. 



" The orifice leading to the pyloric cavity of the stomach re- 

 sembles in some respects a true pyloms ; besides the additional 

 muscular fibres, the greater part of which are circularly disposed, it 

 is provided ^ith a circular and valvular production of the inner 

 membrane of the stomach of 3 lines in extent; diameter of the 

 orifice 9 lines. Immediately beyond this vai ve are the orifices of 

 the two caecal appendages, situated lį inch apart at the upper and 



