OF DIGESTION. 



167 



bowels are seen moving in the manner of a bunch of earthworms, 

 whence the name of vermicular motion, which has been given to it. 

 The gall ducts enter the small intestine about six inches after it 

 leaves the stomach, and the moment the bile mingles with the 

 chyme, a chemical change takes place, and the separation of the 

 nutritious parts from the refuse begins to go on. A creamy-looking 

 white fluid, called chyle, appears on the surface of the food next to 

 the mucous membrane, and it is sucked up by an infinity of small 

 vessels called the absorbents. The use of the great length of the 

 alimentary canal is, that every part of the food may be turned 

 about, and successively be presented to the mouths of these vessels, 

 so as to have its nourishing particles fully removed. The food 

 becomes gradually thicker and drier as it passes down, and is 

 stained of a yellow color, from the admixture of bile, but it still 

 remains perfectly sweet, and without any unpleasant smell, until it 

 gets into the large intestines, where it puts on the character of faeces 

 or useless matter. 



Intestines, Lacteals, and Mesentery Glands. 



T D T D, the chyle duct ; L, lacteals ; M G, mesenteric glands, several of which are here repre- 

 sented ; S, spinal column. The folding structure of the intestines is here well represented. 



The large- intestine is seen in the figure to commence by a blind 

 end, into the side of which the small intestine opens. A valve is 

 here placed, to prevent the regurgitation of the faecal matter into 

 the small bowels. A curious appendage, about the size of a large 

 earth worm, is seen hanging from the end of the commencement of 

 the large gut, which in man is merely rudimentary. In purely 

 graminivorous animals, the intestines are much longer than in man, 

 and have several of these contrivances, for delaying the less nutri- 



