EuMiNAHTiA. MAMMALIA.- 



-EUMINAMIIA. 



155 



teotli 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 tlie ruminants not included 

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

 are closely approximated to the incisors, and, forming 

 a very close resemblance in fonn and size, are easUy 

 mistaken for true incisors. In the tji^ical species, also, 

 there is always a wide unoccupied space inteiTening 

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

 when the latter are present in the upper maxiUary bone, 

 a similar, though somewhat shorter uiterspace, is corre- 

 spondingly manifest above. The tyiwoal species hkewise 

 usually chsplay six molar teetli on each side of eitlier jaw, 

 their flattened crowns bemg surmomited by two double 

 and irregularly crescent-shaped folds of enamel ; the 

 convex outline being directed inwards m tlie superior 

 series, and outwards below. But die most interesting 

 character by which all the species are noted, consists in 

 the multiple character of the stomach, wliich is divided 

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

 (tig. 53). This organ — wo say it unliesitatmgly — affords 

 one of the most striking illustrations of the special evolu- 



tion of a complex mechanism from the general or more 

 simple typo of structm'e seen in the majority of mam- 

 malia, whilst, to the mind of an unprejudiced ti-uth- 

 seeker, it irresistibly indicates evidence of creative 

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

 lessened by tlie easily demonsti'ated fact, that two if 

 not tliree of its divisions are essentially modified dilata- 

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

 department of natural history knowledge too important 

 to be slm-red over ui a work like the present ; there- 

 fore, before proceeding to explain the ruminating fimc- 

 tion, we are careful to notice tlie foim and mechanism 

 of this beautifully constructed orgarusm. 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 

 romided at the angles, and occupies no uiconsiderablc 

 portion of the entire abdominal cavity of the annual . 

 Certain constrictions externally, corresponding with 

 folds of the lining membrane niternally, cause this organ, 

 when carefully separated from its other stomachal con- 

 nections, to assume the appearance of an enormously 



Fig. 53 



^'■ 



^?>.. . -.,., 



StoUiach of the SliCL'p. 



distended coil of mtcstuic, bent upon itself in the form 

 of the letter S. In the ty|)ical rumuiants 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 smface ; the villi forming small, 

 flattened, prominent, pedimcidated masses, in shape 

 resembling racket bats. Such is the general character 

 of the paimch in ordinary ruminants ; but ui the aber- 

 rant camcline genera we find very material dift'erenoes. 

 Instead of presenting a rugous internal surface crowded 

 with those baton-like viUosities, 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 gi'oups, one on the right 

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

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

 measra'ing about one foot and a half in length and six 

 inches in breadth. The cells of each group are disposed 

 in parallel rows, separated from one another by strong 

 muscular bands, given off from a single large bimdle of 

 fibres, wliich commences at the upper extremity of the 



paunch, and proceeds m a longitudinal direction, so as 

 to diviile the cavity into two compartments. The 

 muscular fasciculi are arranged transversely, and give 

 off secondary bmidles at tolerably regular intei-vals, so 

 that the roimdcd orifices of each cell are guarded by 

 powerful square-shaped muscular lips. Some of the 

 pouches are more comphcated than oUiers, bemg sub- 

 divided into numerous smaller bags by foldings of the 

 internal lining membrane. The largest of the reservoirs 

 in the adult dromedary have, when distended, a depth 

 and width of about three mches. A structure analogous 

 to this is fomid hi the Uamas ; but it is not so sti'ongly 

 developed. This leads us, in tlie nest place, to de- 

 scribe the second stomach of the ruminants, othermse 

 caUed 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, presenthig 

 a globular outhiie, and forming a sort of cid-de-sac 

 between the first and tliird stomachs. Its most char- 

 acteristic featm-e is seen in tlie presence of multitudes 

 of polygonal cells, from which circumstance it has 

 been popidarly called the honey-comb bag. In some 

 species, as, for example, m the rem-deer and giraffe, 



