DIGESTIVE SYSTEM. 319 
In some cases, the claws in which the toes terminate, by 
penetrating the substance of the object, retain it more se- 
curely. These claws are sometimes double on the same 
finger, and have their motions so arranged, that they seize 
the object like a pair of forceps. 
In place of arms, protected or supported by hard articu- 
lated substances, many animals possess soft flexible threads 
of various thickness, termed tentacula. 'These encompass 
the objects used as food, and convey them to the mouth. 
Sometimes, for the more certain retention of the prey, 
these tentacula are armed with suckers, which adhere rea- 
dily to any surface to which they are applied. 
Some animals are furnished with a lengthened snout, 
for the purpose of turning up the ground in search of food, 
as the sow and mole. In the case of the elephant, the 
snout is so constructed at the extremity, as to grasp an ob- 
ject, and so flexible throughout, as to serve the purpose of 
tentacula. 
These organs for seizing which have been enumerated, 
though, in general, situated in the anterior part of the body, 
in the neighbourhood of the mouth, do not enter into the 
composition of that opening. Those which follow, how- 
ever, form constituent parts of that organ. 
The margin of the mouth itself, termed the Zips, is, in 
many cases, well adapted for the purpose of seizing objects. 
In some cases, they are capable of beg protruded to some 
distance, and form a tubular proboscis; and being beset 
with teeth or prickles, retain possession more secure of the 
objects of their pursuit. J 
In some instances, the tongue is used as an instrument 
of seizure. In which case it is capable of being extended 
considerably beyond the margin of the mouth. 
In many aquatic animals, a variety of means are em- 
ployed, in order to produce currents’ in the water, to bring 
