872 



PACHYDERMATA. 



sac issuing from the posterior aspect of the car- 

 diac extremity of the stomach and projecting 

 towards the right side. The construction of the 

 interior of this stomach is still more extraordinary 

 than its external appearance, for it is so divided 

 by septa, t hat food coming into this viscus through 

 the oesophagus may pass by different channels, 

 either into the central portion, which seems pro- 

 perly entitled to the name of stomach, or into 

 either of the great diverticula appended to it. 

 The inferior walls of the central stomach have 

 nine or ten cavities in them, something like 

 those of the Camel and Dromedary. The lining 

 membrane both of the stomach and diverticula 

 is granular and wrinkled except near the py- 

 lorus, where the parieles become smooth and 

 folded into numerous plica; somewhat resem- 

 bling those of the third stomach of a ruminant, 

 although there is no probability that rumination 

 occurs in the animal under consideration. 



In the hog tribe the proportionate dimensions 

 of the alimentary canal are very great when 

 compared with the size of the animal's body, 

 the large and small intestines of the Hog or 

 wild Boar measuring together from sixty to 

 sixty-five feet in length, the large intestines 

 alone being in the wild Boar thirteen and in the 

 domestic Hog fifteen feet long. The stomach 

 is capacious, the entrance of the oesophagus 

 being situated nearly in the centre of its lesser 

 curvature, so that the cardiac cul de sac is 

 exceedingly large, and is moreover prolonged 

 into a kind of cowl-shaped appendage, which 

 gives it a very peculiar aspect. On opening 

 the stomach the epithelium of the oesophagus 

 is found to be prolonged for some distance into 

 its interior, where it covers a square space of 

 considerable extent, the borders of which are 

 well defined. At the entrance to the pylorus 

 there is a large nipple-shaped projection up- 

 wards of an inch in length in the full-grown 

 animal ; and moreover, however much the 

 stomach may be distended, there always re- 

 mams a deep fold crossing it at its upper part, 

 between the oesophagus and the pylorus, and 

 another equally extensive bounding the com- 

 mencement of the great cardiac cul de sac, 

 these folds evidently indicating a relationship 

 with the more complex stomachs met with in 

 ruminating animals, especially as the lining 

 membrane only assumes a villous aspect in the 

 pylonc region of the viscus. 



The liver consists of four lobes, and there is 

 a distinct gall-bladder, either lodged in a deep 

 fissure, or imbedded in the substance of the 

 middle lobe. The spleen is long, flat, and 

 somewhat of a prismatic shape, and the pan- 

 creas consists of three portions, which unite 

 near the pylorus. 



The Hyrux Cupensis has a stomach which to 

 a certain extent reminds the anatomist of the 

 complex condition of that viscus met with in 

 many animals nearly related to the Pachyder- 

 n ata. The cardiac extrenmy is large, and 

 forms a capacious cavity, which is divided by a 

 deep constriction from a second compartment 

 of smaller dimensions, which opens into the 

 pylonc portion of the organ. The whole viscus 

 is m 01 cover so bent upon itself owing to the 



smallness of the lesser curvature, that the py- 

 lonc and cardiac extremities are almost in con- 

 tact with each other. The coacum is likewise 

 proportionably of enormous size, being larger 

 than the stomach itself, and from this a spirally 

 folded intestine of no very great calibre runs to 

 a kind of second ccecum of large capacity, 

 which has its commencement prolonged up- 

 wards by means of two conical appendages like 

 horns, whence it has been named by Pallas 

 intestinum bicoi*ne, and this last, after becoming 

 considerably diminished in size, terminates in 

 the rectum. 



Salivary glands. The salivary organs are 

 very large. In the Hog there are two sublingual 

 glands ; one, which is very long and narrow, 

 accompanies the duct of the maxillary gland, 

 and is composed of small lobes of a pale reddish 

 colour ; the orifice of its excretory duct is near 

 that of the maxillary. The second sublingual 

 gland is placed in front of the former, and is 

 of a square form ; it discharges its secretion 

 through eight or ten short ducts, which pierce 

 the mucous membrane of the mouth. The 

 parotid is large, its duct opening opposite the 

 third molar tooth ; and in addition to these 

 there are the molar glands, which form two 

 elongated masses, situated along the alveoli of 

 the superior and inferior molar teeth, and 

 extending forward as far as the canines ; these 

 pour their secretion into the mouth through 

 numerous little orifices. 



Os hyoides. The os hyoides in the Elephant 

 has its body or central portion, which resembles 

 a flattened lamina, slightly arched from below 

 upsvards, consolidated with the posterior corn ua, 

 which divide into two branches as they curve 

 gently backwards and inwards. The anterior 

 corn ua articulate with the styloid process of the 

 temporal. In other Pachyderms the general 

 disposition of the hyoid pieces is very similar 

 to the above, but in the Rhinoceros their ar- 

 rangement approximates what is met with in 

 horned ruminants, the anterior cornua being 

 articulated to the styloid by an intervening- 

 osseous piece. 



The laryngeal apparatus exhibits nothing 

 extraordinary in its arrangement. 



Circulatory and respiratory systems. The 

 organs of circulation and respiration likewise, 

 in their general arrangement, differ from those 

 of other Mammalia in no important particular. 

 We may, however, notice one or two deviations 

 from the usual type in the origins of the chief 

 venous and arterial trunks. 



In the IJyrax the arch of the aorta gives oft' 

 the arteria innominata, which divides into the 

 right subclavian and the two common carotids, 

 and then a second single trunk, which is the 

 left subclavian. 



The Elephant in several points of its economy 

 exhibits remarkable affinities with the Roclen- 

 tia, in proof of which the correspondence of 

 the structure of its heart with that of some of 

 the Rodents is very striking. Thus the right 

 auricle receives three venae cavae, a right and a 

 left superior and an inferior, which latter pre- 

 sents the usual arrangement. Moreover, the 

 Eustuchian valve, which is placed between 



