PREHENSION OF FOOD. 
163 
and fatty matters, termed chyle , is separated from the matters 
that are to be thrown off: this process, which is the second 
stage of true digestion, is termed chylification. The rejected 
portions of the food, with secretions poured into the alimen¬ 
tary canal, find their way out through the intestinal tube ; 
and are voided at its terminal orifice by the act of defecation. 
And lastly, the nutritive materials are taken up by absorption 
into vessels that are distributed upon the walls of the diges¬ 
tive cavity, and undergo a gradual change, by which they are 
converted into blood. These two processes are called absorp¬ 
tion and sanguification (or manufacture of blood). Each of 
the foregoing stages will now be separately considered. 
Prehension of Food. 
172. The introduction of aliment within the entrance to the 
digestive cavity is accomplished in various methods in dif¬ 
ferent animals. In the Mammalia in general, the aperture of 
whose mouth is guarded by fleshy lips, these, with the jaws 
and teeth, are the chief instruments of this operation. But 
in Man and the Monkey tribe the division of labour is 
carried further; the food being laid hold of by the anterior 
members, or hands, and by them carried to the mouth. 
Where the hand has the power of grasping, and especially 
where the thumb can be opposed to the fingers, the action of a 
single member is sufficient; but there are several animals 
which, like the Squirrel, use both limbs conjointly to hold 
their food, the extremity not having itself the power of grasp¬ 
ing. The Ant-eaters, Woodpeckers, Chameleons, and other 
insect-eating animals, obtain their food 
by means of a long extensible tongue; 
this either serving to transfix the insect, 
or being covered with a viscid saliva 
which glues it to the surface. The Giraffe 
uses its long tongue to lay hold of the 
young shoots on which it browses ; and 
the Elephant employs its trunk, which is 
nothing else than a prolonged nose, for 
every kind of prehension (fig. 82). Many 
of the Invertebrata are furnished with 
little appendages round their mouths by 
which the food is conveyed into them ; such are the palpi 
m 2 
Fig. 82 
Head of Elephant. 
