RUMINANTIA. 



537 



denominated the honey-comb-bag. The cells 

 are particularly shallow in the Rein-deer and 

 Giraffe, being circumscribed by very narrow 

 laminae, scarcely elevated above the level of 

 the mucous surface. The lining membrane 

 is further characterised in the horned rumi- 

 nants by a cuticular covering developing a 

 great number of minute and sharply pointed 

 conical papillae, which occupy every part of 

 the cavity, but are most prominently marked 

 along the ridges of the laminae, imparting to 

 these folds a denticulated aspect. In the 

 Camels and Llamas the honeycomb-cells ac- 

 quire a form and capacity strictly analogous 

 to the water-cells of the paunch ; but there 

 are some slight modifications of structure, 

 apparently conformable with the more tem- 

 porary or immediate purposes which they 

 subserve. The apertures of the cells of the 

 rumen destined to retain water for a 

 lengthened period are narrow and guarded 

 by productions of the lining membrane, while 

 those of the reticulum, constantly parting with 

 their aqueous contents during the ordinary 

 act of rumination, are more patent, and not 

 covered in by special membranous folds; 

 moreover, in the distended condition of the 

 cells, the external surface of the paunch is 

 marked by a corresponding number of vesi- 

 cular bulgings, but in the reticulum the 

 walls remain smooth and do not exhibit any 

 very evident traces of the contained water- 

 cells ; their internal subdivisions are likewise 

 more numerous and complicated than in the 

 rumen. Another distinction already al- 

 luded to between the typical and akera- 

 tophorous species, obtains in the absence of 

 an internal cuticular epidermis in the bonnet 

 of the Camelidae. In all ruminants at the 

 anterior border of the second stomach is 

 situated a short demi-canal, constituting the 

 remains of that portion of the oesophagus 

 not involved in the great gastric dilatations, 

 two of which we have now described. This 

 elongated channel very well shown in the 

 accompanying woodcut, fig. 359., forms a 

 bond of communication between the gullet 

 and the three first digestive cavities, and it 

 is provided with an extension of the mus- 

 cular tunics of the oesophagus, modified to 

 suit its twofold office, to which we shall again 

 have occasion to refer when speaking of the 

 ruminating function in detail. 



The third stomach (d,fig. 359.), commonly 

 called the Psalterium, Manyplies, Omasus or 

 Feuillct, intervenes between the water-bag 

 and the fourth or true digestive cavity, com- 

 municating with the former by a constricted 

 orifice and with the latter by a very wide 

 opening. It is the smallest of the stomachal 

 viscera, subglobular in form, and smooth ex- 

 ternally ; but the extent of its absorbing sur- 

 face bears no relation to the diminished bulk 

 of the organ, seeing that it is enormously in- 

 creased by a remarkable folding of the internal 

 lining membrane, the duplicatures of which 

 resemble the leaves of a book, hence the 

 names above indicated. The laminae are 

 longitudinally disposed, and in the empty 



condition of the viscus are closely applied 

 against each other. In breadth they exhibit 

 proportionate differences, so that we find an 

 alternating assemblage of lamina? presenting 

 three several degrees of development ; one, 

 a very narrow fold, another, very broad, 

 and a third of intermediate width, serially 

 intercalated between the two. Altogether 

 about forty such septa have been counted in 

 the Sheep, and more than double that number 

 in the Ox. The internal surface is beset 

 throughout with small conical, pointed pa- 

 pillae, similar to the villi of the reticulum, 

 those placed at the free margins of the folds 

 being paramount. In Camelidae the psal- 

 terium is greatly elongated, attenuated at 

 either extremity, and three or four times 

 more bulky ^than the water-bag ; otherwise, 

 its organisation conforms with the pecu- 

 liarities observable in the horned species. 



The fourth stomach (e, fig. 359.), techni- 

 cally termed the Reed, Abomasus, or CaiUette, 

 constitutes the true digestive apparatus, ana- 

 logous to the simple gastric organ of the non- 

 ruminating vertebrata. It is about one third 

 of the size of the paunch, and smooth ex- 

 ternally, has an elongated pyramidal figure, 

 and terminates by a narrow tubular portion 

 at the pyloric extremity, the muscular tunics 

 at this point acquiring a considerably in- 

 creased thickness. Internally the secreting 

 membrane is distinguished by irregularly 

 disposed longitudinal folds, slightly elevated 

 above the surface and intercommunicating by 

 smaller rugae of the same nature, having an 

 oblique or transverse direction. There are 

 no papillary eminences like those in the re~ 

 ticulum and manyplies, the lining membrane 

 being soft, highly vascular, and occupied by 

 the follicular openings of true gastric glands 

 as in the human stomach. At the pylorus, 

 in addition to the ordinary narrowing usually 

 found at this part, there exists a special val- 

 vular process, developed from the mucous 

 membrane at the commencement of the duo- 

 denum ; in the Giraffe this protecting fold 

 is situated just within the stomach (Owen). 

 In the akeratophorous Ruminantia the reed 

 is relatively smaller than in the horned 

 species ; in other respects it offers no ap- 

 preciable difference. 



The ruminating function is characterised by 

 the following phenomena : The food, on 

 being received into the mouth, undergoes a 

 very partial mastication, and in this crude 

 state is speedily carried down the oesophagus, 

 where, on arriving at the lower part, the lips 

 of the muscular channel, placed at the en- 

 trance of the three first stomachs, separate, 

 so as to ensure its passage into the paunch, 

 In like manner, subsequent to the act of 

 drinking, the margins of the oesophageal 

 groove open, and the water is conveyed into 

 the cells of the reticulum. In the Camels a 

 proportion of the fluid passes into the first 

 cavity, there to be retained by the great 

 water-pouches, as a special provision against 

 those contingencies which their mode of ex- 

 istence involves. While the coarse vegetable 



