222 VERTEBRATE ANIMALS. 
“salivary glands.” From the mouth the food passes through a 
muscular tube—the gullet, or wsofhagus (fig. 120, g)—to the 
proper digestive cavity, or stomach (s). Here it is subjected to 
the action of a special digestive fluid—the “ gastric juice”—and 
is converted into a thick pasty 
7 fluid, which is called chyme. From 
the stomach the chyme passes into 
a long convoluted muscular tube, 
which is called the “small intes- 
tine” (sw). Here it is subjected 
to the action of two other digestive 
fluids, called the “bile” and “pan- 
creatic juice,” as well as to the 
fluids secreted by the intestine it- 
self. The bile is secreted by a 
large gland, which is known as 
the “liver,” whilst the pancreatic 
juice is produced by another, 
termed the “pancreas,” both pour- 
ing their secretion into the upper 
part of the small intestine. By the 
combined action of these digestive 
fluids the chyme is ultimately con- 
verted into a milky fluid, which is 
called chyle, when it is fit to be 
taken up into the blood-vessels. 
The small intestine finally opens 
: re into a tube of larger diameter 
Fig, 120.— Digestive system of a . Y : ’ 
Mammal. ¢Gullet, orcesophagus; Which is called the “large intes- 
s Stomach; sv Small intestine; tine” (lm), and this opens on the 
ine Large intestine ; x Large in- surface of the body by an anal 
testine terminating in its final por- . . 
odbeaied the Grectum?! aperture. In the large intestine 
the last remaining portions of the 
food which can be rendered useful are absorbed into the blood, 
the indigestible portions: being ultimately got rid of as useless. 
The fluid products of digestion (chy/e) are chiefly absorbed from 
the intestinal canal by a set of special vessels, which are present 
in all Vertebrates, and which are called the /actea/s, from the 
milky fluid they contain. These lacteals combine to form a 
large trunk, by which their contents are ultimately added to 
the circulating blood. Part of the products of digestion are 
