SPLANCHNOLOGY. - No parts of the ana tomy of the monkeys are, perhaps, inore inter esting than the pouches of the larynx. I have published a great number of observations about them, by which is proved : 1. that they exist in the Chimpanzee, the Orang-cetan, the Sianiang, the Senznopitheci, Cercopitheci, Inui, and the Cynocephali; 2. that they are larger in the males than in the females; 3. that they grow with the age of the animal, and are consequently the largest in the most aged ; 4. that they are chiefly a dilatation of the laryngeal ventricles in the Chimpanzee and in the Orang-cetan, but that in the other monkeys they are in direct communication with the cavity of the larynx, by an aperture at the basis of the epiglottis ; 5. and that they arewanting in the Gibbons, the Cercopithecus radiatus, the Cercopithecus mona and Cynocephalus porcarius. it is very difficult to derive any physiological conclusion from all these anatomical state ments. The most probable hypothesis seems to be, that these receptacles of air, which send their prolongations between all the mus cular fascicles (fig. 131), seem to diminish the specific gravity of the body, in the action of climbing, and that they are consequently passive organs of movement. I have offered this opinion in greater detail in my work upon the Chimpanzee, and I refuted there the opinion that they were connected with the utterance of voice. The other parts of the laryngeal apparatus do not differ much from those of nzan, with the exception of the hyoid bone, which has much of the human form in the Chimpanzee, in the Orang-wtan, and in the Gibbons, but the basis of which is changed into a convex and elongated shield in the other monkeys, in which the laryngeal pouch opens below the epiglottis.
In the form and structure of the heart and the lungs, there is no difference between the In the organs of digestion, there is much difference to be observed in the various spe cies of monkeys. The Apes, viz. the Chim panzee, the Orang-cetan, and the Gibbons, offer much resemblance in these organs to those of ?nan. The stomachs of the four young Orangs (elan, which I dissected, had quite the human form and structure. But in the adult de
scribed by Sandifort, the pyloric portion is separated from the cardiac by a very narrovv constriction, and the tunics of the pyloric portion are very thick. In the ccecum the resemblance to nzan is still more striking, by the existence of a vermiform appendix, which is separated from the intestine by a constric tion in the Chimpanzee, is continuous with the intestine in the Orang-cetan, and is very small, and almost rudimental, in the Gibbons. Consequently there is also a descending gra dation in this organ, in the same manner as in all the other points of organisation ; for the appendix is wanting in all the other monkeys, in which the ccecum is moderately large and terminates in an obtuse cone. The stomach of the other species has not the same oblong form in the transverse direction, as the sto mach of the Simice and of man, but acquires a more globular form, especially in the Cyno cephali. In this way it forms a transition to the form of the stomach in the Carnivora. A very interesting deviation is afforded by the Seninopitheci, in which Wurmb, Otto*, and Owen ± found (as I also saw confirmed in the S. maurus) a complicated form and construc tion of the stomach, viz., its division into three portions : 1. cardiac pouch, with smooth pari etes, slightly bifid at the extremity ; 2. a middle, very wide, and sacculated portion ; 3. a narrow, elongated canal, sacculated at its commencement, and of simple structure to wards its termination. This complication of the stomach seems to be connected with the vegetable food of the Semnopitheci, which consists only of fruits, and it is also a repe tition of the divisions we find in the stomach of the Pteropi, the Hyrax capensis, the Bra dypoda, the Cetacea, and in the utmost per fection in the Ruminantia. A curious fact connected with this sacculated division of the stomach is the existence of bezoars in the Senznopitheci. They are said to be smaller and rounder than those produced by the goats. gazelles, and antelopes.