SIJEEP HUSBAxNDRY IN THE SOUTH. 451 



The reticulum or honey-comb is composed of the same number of coats, 

 fulfilling similar functions. But the mucous coat, in addition to minute 

 papillce, is covered with elevations arranged in pentagons and sexagons 

 of diiferent sizes, somewhat resembling a honey-comb, except that the 

 cells are larger and shallower. 



The maniplus has the same four coats. Its floor is a continuation of 

 the oesophagean canal. From its roof depend many parallel folds of the 

 cuticular coat — here thicker and stronger than in the other stomachs — 

 reaching nearly to its floor. The cuticle is covered toward the edges of 

 the folds, with hard, bony processes, shaped like fangs, or cones bent in a 

 curvelinear form, and pointing toward the entrance of the stomach. The 

 interior of each fold or leaf contains muscles which impart to it the power 

 of a peculiar and forcible motion. There are forty-two of these folds in 

 the maniplus of the sheep — occasionally forty-eight. They do not all 

 equally nearly approach the oesophagean canal, but are disposed in groups 

 of six — one of the central ones of each nearly reaching the canal or floor 

 of the stomach — the others on each side growing shorter and shorter, so 

 as to form a series of irregular reentering angles. 



The abomasum is the digesting stomach, where the gastric juices are 

 secreted, and where the pultaceous food is converted into chyme. It is 

 funnel-shaped, and its lower extremity connects with the intestines, as 

 shown in the cut. The cuticular lining of the three preceding stomachs 

 is wanting in this. The mucous coat is disposed in the form of rugai or 

 shallow folds, arranged longitudinally with the direction of the stomach, 

 and from this membrane the gastric juices are secreted. 



The cowparative size of the four stomachs will be sufliciently seen in 

 fig. 47. 



Where the oesophagus enters the rumen, it terminates in what is called 

 the oesophagean canal, a continuation of the former constituting the roof 

 of the latter. The bottom or floor of this canal is formed of divided por- 

 tions or folds of the upper parts of the rumen and reticulum — muscular 

 " pillars" or "lips," as they are sometimes denominated — which may re- 

 main closed so that the food will pass over them into the third and fourth 

 stomachs — or they may open, permitting the food to fall between them, 

 as through a trap-door, into the first and second stomachs. It is probable 

 that the opening of these lips, as food passes over them, depends some- 

 what upon a mechanical effect, and somewhat upon the will of the animal. 

 Fluid and soft pultaceous food fit for immediate digestion glide over them. 

 But most of the food of the sheep, like that of other ruminating animals, 

 is swallowed with little preparatory mastication ; and these untriturated 

 solids drop down through the first opening above described into the ru- 

 men. It is certain, however, that the animal can, at will, also cause water 

 to pass through the opening into the first stomach. This would be neces- 

 sary in the animal economy, and the water is always found there. 



When the food has entered the rumen, the muscular action of that vis- 

 cus compels it to make the circuit of its different compartments, and, in 

 time, the food later swallowed foi'ces it on and up to near the opening 

 where it originally entei'ed. In its passage it is macerated by a solvent 

 alkaline fluid secreted by the mucous coat. The papillae of that coat are 

 supposed to influence the mechanical action of the contents of the stomach, 

 and perhaps, to a certain extent, to aid in triturating them. The food 

 performs the circuit of the stomach, and is ready for re-mastication, ac- 

 cording to Spallanzani, in from sixteen to eighteen hours. By a muscular 

 eff*ort of the stomach, a portion of it is then thrown over the membraneous 

 valve or fold which guards the opening from this into the second stomach. 



(801) 



