100 OF THE VESSELS 



mechanism. The figure and position of the stomach, (I 

 speak all along with a reference to the human organ) are 

 calculated for detaining the food long enough for the action 

 of its digestive juice. (PI. XVIII. fig. 1.) It has the shape 

 of the pouch of a bag-pipe ; lies across the body ; and the 

 pylorus, or passage by which the food leaves it, is somewhat 

 higher in the body, than the cardia or orifice by which it 

 enters ; so that it is by the contraction of the muscular 

 coat of the stomach, that the contents, after having under- 

 gone the application of the gastric menstruum, are gradually 

 pressed out. In dogs and cats, this action of the coats of 

 the stomach has been displayed to the eye. It is a slow 

 and gentle undulation, propagated from one orifice of the 

 stomach to the other. For the same reason that I omitted, 

 for the present, offering any observation upon the digestive 

 fluid, I shall say nothing concerning the bile or the pan- 

 creatic juice, further than to observe upon the mechanism, 

 viz. that from the glands in which those secretions are 

 elaborated, pipes are laid into the first of these intestines, 

 through which pipes the product of each gland flows into 

 that bowel, and is there mixed with the aliment, as soon 

 almost as it passes the stomach ; adding also as a remark, 

 how grievously this same bile offends the stomach itself, yet 

 cherishes the vessel that lies next to it. 



Secondly, We have now the aliment in the intestines, 

 converted into pulp, and, though lately consisting of per- 

 haps ten different viands, reduced to nearly an uniform sub- 

 stance, and to a state fitted for yielding its essence, which 

 is called chyle, but which is milk, or more nearly resem- 

 bling milk than any other liquor with which it can be com^ 

 pared. For the straining off of this fluid from the digested 

 aliment in the course of its long progress through the body, 

 myriads of capillary tubes, i. e. pipes as small as hairs, open 

 their orifices into the cavity of every part of the intestines. 

 (PI. XIX.) These tubes, which are so fine and slender as 

 not to be visible unless when distended with chyle, soon 

 unite into larger branches. The pipes, formed by this 

 union, terminate in glands, iiom^ which other pipes of a still 

 larger diameter arising, carry the chyle, from all parts into 

 a common reservoir or receptacle. This receptacle is a 

 bag, large enough to hold about two table spoons full ; and 

 from this vessel a duct or main pipe proceeds, climbing up 

 the back part of the chest, and then ereeping along the 

 gullet till it reach the neck. Here it meets the river. Here 

 it discharges itself into a large vein, which soon conveys 



