248 MANUAL OF AGEICULTURE. 



amylaceous bodies into soluble saccharine bodies. The mass 

 passes through the gullet, entering the stomach at the cardiac 

 orifice. There it is acted upon by several secretions, the princi- 

 pal of these being the gastric juice, whose properties closely re- 

 semble those of hydrochloric acid. When the various com- 

 pounds are nearly dissolved, they are passed on through the 

 pyloric orifice of the stomach to the intestines in the condition 

 called chyme. Chyme is a pasty substance, containing dissolved 

 saccharine matter and undissolved starch, albuminous bodies 

 broken up and wholly or partially dissolved, oleaginous bodies 

 broken up but undissolved, such solid indigestible portions as 

 have been enacted upon by the gastric fluids, and some of the 

 liquids swallowed along with' the solid food. The intestines, ac- 

 cording to their diameter, are divided into the large and small. 

 Continuing from the stomach, the small intestine is nominally 

 distinguished as the duodenum, jejunum and ileum ; and the 

 large intestine as the CcCcum, colon, and rectum. The latter dis- 

 tinction is less merely nominal, the rectum being less puckered 

 or convoluted than the other two. At the union of large and 

 small intestines occurs the ileo-cffical valve, allovving a passage 

 but one way from the small to the large. 



Ere the chyme has entered far into the duodenum it is sub- 

 jected to the action of the intestinal juices organised in various 

 glands. Chief are the bile and pancreatic juices, secreted by the 

 liver and pancreas respectively. These serve further to dissolve 

 the albuminous compounds, of emulsifying or saponifying the 

 oily constituents of the chyme, and of recommencing the conver- 

 sion process of starch into sugar, which had been arrested by the 

 gastric fluids. And thereby all are alike rendered capable of 

 direct absorption. The chyme continuing its course through the 

 intestines, has its available compounds absorbed and carried to 

 the blood, and the insoluble, indigestible residue voided from the 

 rectum. 



At this stage it may be as well, before adverting to the jjro- 

 cesses of absorjotion and nutrition, to consider the constitution 

 and cii^culation of the blood. 



Like the sap of j)lants in its grand work of supplying all the 

 animal tissues with the necessary food for health and mainten- 

 ance, it has to discharge the additional functions of keeping up 

 the animal temperature in every part, and of removing waste 

 tissue substance and matter deleterious to life. Actually it 

 consists of a colourless fluid containing innumerable minute 

 globules, — " corpuscles," — the greater part of which are red in 

 colour, and give the blood its characteristic hue. Its fluid 

 portion, the liquor sangitinis, is composed of the " serum," hold- 

 ing fibrin and other compounds in solution. The fibrin exposed 

 to the atmosphere has a tendency to coagulate, whence blood 



