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small curvature; but leaves a well-marked semi-oval pouch to the left the pyloric end loses in calibre and gains in thickness of its coats, the inner one projecting in wavy longitudinal folds: the pylorus is a small constriction. In a male Galeopithecus Temminckii, measuring from the apex of the nose to the root of the tail 1 foot 4 inches, the small intestines were 4 feet 4 inches, the cæcum 1 inch, the large intestines 7 feet 7 inches.1

In the Aye-aye the œsophagus has a course of about a third of an inch in the abdomen before terminating at the cardiac orifice. This is situated, as in most Lemurs, nearer the pylorus than the cardiac end. The stomach is of a full, subglobular form: the pyloric end projects about half an inch below and to the right of the pylorus. A narrow glistening tract of fine aponeurotic fibres runs parallel with, and a little below, the short curvature between the cardiac and pyloric orifices, and from this tract the fibres of the outer muscular layer radiate. A narrow but well-marked crescentic fold projects into the cavity from the lesser curvature, four lines to the right of the cardia, subsiding about an inch down the fore and hind walls: this fold appears even when the cavity is fully distended, and it marks out internally the division between the cardiac and pyloric compartments. The pylorus is a subcircular aperture, above which projects a short thick longitudinal prominence. The duodenum, after its usual curve, crosses the spine below the root of the mesentery, then turns up the left side to commence the three principal folds of the small intestine, on the border of the mesentery, by which, with the cæcum, they are freely suspended. A duplicature of peritoneum is continued from the end of the duodenum, and from the lower part of the beginning of the colon, to the first lumbar vertebra, attaching them thereto. The colon, after a course of 3 or 4 inches, forms a long narrow fold, 5 inches in length, then passes to the left, above and behind the root of the mesentery, and descends along the left lumbar and hypogastric regions to form the rectum.

The small intestines are rather more than three times the length of the body the cæcum is about one-fifth that length; measuring 2 inches 7 lines: for the first inch it is 10 lines in diameter, but suddenly contracts to a diameter of 3 lines; terminating rather obtusely, and resembling an appendix vermiformis; but this is not marked off by any valvular structure from the wider part of the cæcum, and it is continued, as in the human foetus, directly from

In several shot on the hills at Pinang, the stomach contained vegetable matter, but no remains of insects. In confinement plantains constitute the favourite food.' LXXXII". p. 8.

the end of the wider part, or cæcum proper. The large intestines are about 1 foot 10 inches in length. The colon, moderately distended, is 1 inch 2 lines in diameter at its commencement, and gradually decreases in width. Beyond the first enlargements it is not sacculated, but is slightly puckered on a longitudinal band, which may be traced a few inches from the beginning of the gut, where two or three pouch-like protrusions appear on inflation. The ileo-colic aperture is slit-shaped, bounded by two low ridges, that next the cæcum being most produced.'

This type of cæcum is repeated in Stenops javanicus with a longer and narrower vermiform' termination : 2 in Stenops tardigradus

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328

this part is shorter :3 in Tursius, Perodicticus,5 Otolicnus, and the Galagos, it is wanting, and a moderately long and wide cæcum terminates obtusely, without contracting in Galago calabariensis it is comparatively short: in Galago moholi, with a more efficient form of molars for mastication, the cæcum is more than twice the length in proportion to its calibre, and it is puckered by a mesenteriole into five or six short folds, fig. 327. The cardiac part of the stomach is large in all Lemurines, fig. 328, a: but the py

Stomach of Galago Moholi, nat. size.

loric part rarely protrudes to the right of the pylorus, below the beginning of the gut. The duodenum is rather shorter in true

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Lemurs than in Galagos: the cæcum was 7 inches long in a Lemur Mongoz; it was loosely suspended, as in other Lemurida.

In the small Platyrhines (Midas, Jacchus) the oesophagus is continued a short way into the abdomen, and the stomach resembles that in Lemurida: the duodenum becomes free in passing to the left. The cæcum is of moderate length, cylindrical, curved: two longitudinal bands are continued from it along the colon. In Jacchus vulgaris the small intestines are twice the length of the body, the large intestines once that length. The cardiac sac of the stomach is large in all Platyrhines, but the cardia and pylorus are less approximate in the larger kinds. In Ateles and Mycetes Cuvier notes a tendency to sacculation along the great curvature. The cæcum is 4 inches long and 1 inch broad in Cebus; in Ateles it is subconical, the base being next the colon. In Mycetes the cæcum is proportionally shorter, but retains the simple unsacculated character.

329

In Cercopithecus the oesophagus, with a short abdominal course, opens into the stomach midway between the left and right ends : in Macacus and Cynocephalus the left sac is relatively less the chief modification is presented by the Doucs, or those tailed monkeys which have a fifth tubercle on a the last lower molar, and are without cheekpouches. In a Semnopithecus entellus which measured 1 foot 8 inches from the mouth to the vent, I found the stomach, fig. 329, 2 feet 7 inches along the greater curvature. To the left

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Stomach, distended; Semnopithecus Entellus. CXXXIX".

curvature, and 1 foot along the lesser of the cardia it forms a large and sub-bifid pouch: the middle and widest part of the stomach is puckered up into several large sacculi: the pyloric portion is long, narrow, curved and sacculated along the line of the greater curvature to within onethird of the distance from the pylorus, where it is simple and gradually contracts to that orifice: the vascularity and structure of the lining membrane of the third division indicates it as the chief

330

seat of true digestion; the wider sacculated divisions have mainly a preparatory and a receptacular function: a firm epithelium is not continued into them from the oesophagus: the greatest circumference of the dilated stomach is 1 foot. The stomach of the Semnopithecus fascicularis is similarly complex but proportionally smaller as are also those of Nasalis larvatus and Colobus ursinus; in which, as in the Semnopitheci, a narrow band of longitudinal fibres, continued from the left end along the greater curve, puckers up the tunics into the larger sacculi, a second band along the lesser curvature contributing in a minor degree to this complexity. Evidence of the accumulation and detention of vegetable food is afforded here, as in Ruminants, by occasional bezoar' concretions.

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Cæcum, Cercopithecus sabæus. CXXII

331

The stomach resumes its simple form in tailless apes: in which the left end is less prominent than in Macaci, and the lesser curvature is of greater extent; the pyloric division is longer, and the entire form less globular: in the Orang the pyloric division shows a rather abrupt bend. The lining membrane of the stomach when in a moderately distended state is devoid of rugæ in all Apes; and the small intestines are without transverse folds of the mucous membrane. The cæcum in Catarhines is always shorter than in Platyrhines, is usually wider and more or less sacculated. In some species of Cercopithecus it is puckered up by four longitudinal bands, of which three are continued along the colon: in most the cæcum is more conical in shape than in Macacus, the apex being narrower and more prolonged, e. g. Cerc. Sabæus, fig. 330. In Hylobates, fig. 331, the vermiform appendage reappears; it is terminal, and in some species short; but is more

Cæcum and vermiform appendage,
Hylobates. CXXII'.

This type of quadrumanous stomach was discovered in an undetermined kind of monkey by Wurmb, in 1785; and, independently, by Otto, in a supposed Cercopithecus in 1824, and described in cxxxvII": it was determined to be characteristic of the natural group, including the genera Semnopithecus, Nasalis, and Colobus, in CXXXVIII", CXXXIX", CXL", and CXLI".

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differentiated as such by its glandular tunic and marked commencement than in Lemurida: the appendix is terminal, but is long and convolute in the Orangs (Pithecus): in the Chimpanzees (Troglodytes) there is a more marked constriction between the appendix and the cæcum. The colon is sacculated and moderately long in all Catarhines: it is loosely suspended by a broad mesocolon, and only in tailless apes does the cæcum begin to adhere, through an incomplete peritoneal investment, to the right hypogastric region.

§ 330. Alimentary canal of Bimana.--The chief characters of the canal in this order are the termination of the gullet almost as

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soon as it has entered the abdomen; the more extensive and closer adhesion of parts of the alimentary canal, as the duodenum, cæcum, beginning and end of colon, to the abdominal walls, which relates to the erect posture; the more definite and finished character of the several parts of the canal; and the modification of the lining membrane of the small intestines, called valvulæ conniventes,' for a more complete and efficient extraction of nutritious matter from the chyme.

The stomach presents a greater extent transversely to the abdomen than in Quadrumana, and the blind left end (saccus cæcus,' Haller) is less extended and expanded than in Monkeys and Lemurs, the œsophagus opening more to the left, and leaving a more extensive lesser curvature,'

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fig. 332, c, P. Anthropotomy distinguishes the cardiac orifice,' fig. 333,a,g; the cardiac pouch' or 'blind sac,' ib. g, d; the 'lesser curvature,' ib. a, e, b; the 'greater curvature,' ib. g, d, f, c, h; the 'pyloric portion,' ib. e, b, b, c; and its orifice or pylorus,' ib. b, b. In a state of moderate distension the length of the

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