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Show 1870.] ANATOMY OF THE PRONGBUCK. 349 arteria innominata, proceeds for about a couple of inches, and then sends off a single branch, which immediately separates into the left brachial and vertebral arteries. Half an inch further on, the innominata splits into three branches, viz. the right brachial, the right vertebral, and the common carotid. The latter is nearly an inch long, and then splits into the right and left carotids and a thyroid branch. 7. DIGESTIVE TRACT AND GLANDS. The stomach consists of four compartments, placed in relation to each other in the ordinary ruminant fashion. The paunch presents considerable proportions when distended, being about a foot in longitudinal and transverse diameter; and its lower end is bifid. The oesophagus, itself narrow and 21 inches long, enters the paunch at its upper and left corner ; but it is also partly directed into the left end of the reticulum, as in the Sheep. The internal thickened folds which partially subdivide the paunch correspond with those of Oris; but the lower one to the right is placed rather more transversely, and does not slant upwards. This gives a greater relative size to the upper compartment of the right half of the rumen in the Prongbuck. The papillae lining the mucous coat are of two kinds. One sort, the longest and largest, are found in the hollows and corner pouches ; these vary from 0*1 to 0*3 inch long, and are club-shaped, with a roughened warty exterior. The second kind are much smaller, shorter, and closely set, and, together, give a granular appearance to the surface; they occupy chiefly the ridges. Besides these villi or papillae, I observed a series of glandular-like bodies scattered widely throughout this first cavity. These were subcircular, cauliflower-like elevations, ranging from 0"*2'" to 0"*3'" inch in diameter, and 0*1 to 0*15 inch in height. On section they seemed aggregations of papillae, but with thickened basal submucous tissue. Although describing these last along with the healthy villous structure, I have reason to believe them a morbid product. The subglobular reticulum has a less restricted neck than in the Sheep. It is between 6 and 7 inches in its long diameter, and about 4 across. As seen in front, after removal of the stomach from the abdomen, the reticulum partially hides the psalterium ; the lower end of the oesophagus and a small portion of the left end of the abomasus also dip behind it. The cells forming the reticulations are rather irregular in size and form, though chiefly hexagonal. They range from 0*2 to 0*3 inch in diameter, and are remarkably shallow. The papillae are acuminate, the largest being found at the summits of the ridge-like boundaries. The psalterium is 3 inches long by 1\ inch wide. It has the usual ruminant plications with intervening shorter ones, covered with short, thick-set, mamillary villi. The fourth cavity, or abomasus, possesses a double curve, and is, as usual, a long cylindrical cavity, narrowing as it approaches the pylorus. The rugae are fully developed, and longitudinal in direction PROC. ZOOL. Soc-1870, No. XXIV. |