SHEEP HUSBANDRY IN THE SOUTH. 453 



If so, by what process ? I think there are other reasons which support 

 the view I have taken, but I will not push the discussion, there not being, 

 so far as I am aware, any questions to be solved by it which directly and 

 practically affect the interests or the practices of the sheep-breeder. 



Let us now observe the course pursued by the food, and the process to 

 which it is submitted, after rumination. It now glides over the trap-doors 

 which open into the first and second stomachs. As it passes over the 

 floor of the third, or the maniplus, the pendant leaves of this viscus, armed 

 with their beak-like protuberances, seize the advancing mass, and squeezing 

 out the fluid and the more finely comminuted portions of the food which 

 escape with it, commence triturating the bulkier fibrous portions between 

 their folds. Their bony papillae give to these folds something of the me- 

 chanical action of rasps, in grinding down the vegetable fibre. The food 

 being now reduced to an entirely pultaceous state, passes into the fourth 

 stomach, or abomasum, where it is acted upon by the gastric juice, and 

 converted into chyme. The amount of food found between the folds of 

 the maniplus, after death, depends upon the time that has elapsed since 

 rumination. It is dry and hard, compared with the contents of the other 

 stomachs. 



The entrance to the fourth stomach — the cardiac opening — is closed 

 against regurgation or vomiting, by a sort of valve, composed of a portion 

 of one of the rugce, before alluded to, which line the interior of this 

 stomach. The pylorus is also closed by a valve, which prevents a prema- 

 ture passage of the contents of the stomach into the intestines. 



The intestines are exhibited in fig. 48, copied from Mr. Youatt's work. 



Before the duodenum enters into (or changes its name to) the jejunum, 

 and about 18 inches from the pylorus, it is perforated by the biliary duct — 

 ductus choledochus — which brings the bile eliminated by the liver, from the 

 gall-bladder, and also the fluid which is secreted by the ^?a?^crcfl5, or sweet- 

 bread, which last is introduced into the biliary duct two inches fi"om its 

 entrance into the duodenum, by another duct or small tube. The com- 

 pound fluid thus inti'oduced into the duodenum exercises various important 

 offices in the digestive and assimilating processes. The bile is supposed 

 to aid in the separation of the chyme into chyle and fecal mattei'^ — or the 

 nutntive parts of the food which are assimilated into blood, from the in- 

 nutritious parts which are discharged as excrement. It also prevents a 

 putrid decomposition of the vegetable contents of the intestines, and seiTes 

 various other useful purposes. 



The chyle — a white albuminous fluid, with a composition differing but 

 little from that of blood — is taken from the intestines by a multitude of 

 minute ducts called lacteals, which traverse the mesentary, constantly 

 uniting as they advance, so as to form larger ducts. These enter the 

 mesenteric glands — small glandular bodies attached to the mesentary — after 

 the passage of which the chyle begins to change its color. The lacteals 

 still continue to unite and enlarge, and finally terminate in the tJioracic 

 duct. In this the chyle is mingled with the lymph secreted from a portion 

 of the lymphatics — another exceedingly minute system of absoibent ducts, 

 which open on the internal and external surfaces of the whole system. 

 From the thoracic duct, the chyle is conveyed to the heart, and enters into 

 the circulation as blood. 



The Spleen. — With the appearance of the spleen or milt — in the sheep 

 a dark, firm, spongy viscus, attached to the rumen, and lying on the left 

 «ide of the belly — all are sufficiently familiar. Its uses and functions in 



(853) 



