MAMMALIA. RUMINANTIA. 



155 



teeth in the upper jaw, the vacant space being occupied 

 by a callous pad ; the lower jaw is invariably furnished 

 with six incisors, but in all the ruminants not included 

 in the last-named family, the two canines of the lower jaw 

 are closely approximated to the incisors, and, forming 

 a very close resemblance in form and size, are easily 

 mistaken for true incisors. In the typical species, also, 

 there is always a wide unoccupied space intervening 

 between the molars and canines of the lower jaw, while, 

 when the latter are present hi the upper maxillary bone, 

 a similar, though somewhat shorter interspace, is corre- 

 spondingly manifest above. The typical species likewise 

 usually display six molar teeth on each side of either jaw, 

 their flattened crowns being surmounted by two double 

 and irregularly crescent-shaped folds of enamel; the 

 convex outline being directed inwards in the superior 

 series, and outwards below. But the most interesting 

 character by which all the species are noted, consists hi 

 the multiple character of the stomach, which is divided 

 into four cavities, so as to provide for the ruminating act 

 (fig. 53) . This organ we say it unhesitatingly affords 

 one of the most striking illustrations of the special evolu- 



tion of a complex mechanism from the general or more 

 simple type of structure seen in the majority of mam- 

 malia, whilst, to the mind of an unprejudiced truth- 

 seeker, it irresistibly indicates evidence of creative 

 design: and we hold this argument to be in no way 

 lessened by the easily demonstrated fact, that two if 

 not three of its divisions are essentially modified dilata- 

 tions of the lower end of the oesophagus, A ! This is a 

 department of natural history knowledge too important 

 to be slurred over hi a work like the present ; there- 

 fore, before proceeding to explain the ruminating func- 

 tion, we are careful to notice the form and mechanism 

 of this beautifully constructed organism. Most people 

 are aware that the first compartment, B, is called 

 the paunch. This is much larger than any of the 

 other so-called stomachs, exhibits a rhomboidal outline 

 rounded at the angles, and occupies no inconsiderable 

 portion of the entire abdominal cavity of the animal. 

 Certain constrictions externally, corresponding with 

 folds of the lining membrane internally, cause this organ, 

 when carefully separated from its other stomachal con- 

 nections, to assume the appearance of an enormously 



Fig. 53. 



Stomach of the Sheep. 



distended coil of intestine, bent upon itself hi the form 

 of the letter S. In the typical ruminants the internal 

 surface is closely beset with villous projections, which 

 impart to the membrane a rough, shaggy aspect, the 

 cogency of which is variously maintained at different 

 parts of the mucous surface ; the villi forming small, 

 flattened, prominent, pedunculated masses, in shape 

 resembling racket bats. Such is the general character 

 of the paunch hi ordinary ruminants ; but hi the aber- 

 rant cameline genera we find very material differences. 

 Instead of presenting a rugous internal surface crowded 

 with these baton-like villosities, the mucous lining mem- 

 brane is conspicuously smooth. The most remarkable 

 feature, however, arises out of the formation of numerous 

 pouches, specially fitted for the reception and retention 

 of water (fig. 54). These sacs, which may be looked 

 upon as so many protrusions of the wall of the viscus, 

 are arranged in two distinct groups, one on the right 

 side and the other on the left ; the former being by far 

 the more numerous, and, in the full-grown dromedary, 

 measuring about one foot and a hah hi length and six 

 niches in breadth. The cells of each group are disposed 

 hi parallel rows, separated from one another by strong 

 muscular bands, given off from a single large bundle of 

 fibres, \vhich commences at the upper extremity of the 



pamich, and proceeds in a longitudinal direction, so as 

 to divide the cavity into two compartments. The 

 muscular fasciculi are arranged transversely, and give 

 off secondary bundles at tolerably regular intervals, so 

 that the rounded orifices of each cell are guarded by 

 powerful square-shaped muscular lips. Some of the 

 pouches are more complicated than others, being sub- 

 divided into numerous smaller bags by foldings of the 

 internal lining membrane. The largest of the reservoirs 

 hi the adult dromedary have, when distended, a depth 

 and width of about three niches. A structure analogous 

 to this is found in the llamas ; but it is not so strongly 

 developed. This leads us, hi the next place, to de- 

 scribe the second stomach of the ruminants, otherwise 

 called the reticulum or water-bag, C (fig. 53). This 

 organ has been regarded by some as a mere appendage 

 of the paunch ; but it is as much entitled to a distinctive 

 recognition as any other of these connected viscera. 

 In respect of size, it is comparatively small, presenting 

 a globular outline, and forming a sort of cul-de-sac 

 between the first and third stomachs. Its most char- 

 acteristic feature is seen in the presence of multitudes 

 of polygonal cells, from which circumstance it has 

 been popularly called the honey-comb bag. In some 

 species, as, for example, hi the rein-deer and giraffe, 



