52 COMPARATIVE ZOOLOGY. 
ous cup-like suckers. So perfect is the adhesion of these 
suckers, it is easier to tear away a limb than to detach it 
from its hold. 
The Articulated animals exhibit a great variety of 
means for procuring nourishment, in addition to the suc- 
torial contrivances already mentioned, the innumerable 
modifications of the mouth corresponding to the diversity 
of food. The Earth-worm swallows earthy matter, which 
it secures with its lips, the upper one being prolonged. 
Other worms (as Laodicea) are so constructed that the 
gullet, which is frequently armed with teeth and forceps, 
can be turned inside out, to form a proboscis for seizing 
prey. Millepedes, Caterpillars, and Grubs have a pair of 
horny jaws moving horizontally. The Centipede has a 
second pair of jaws, which are really modified feet, ter- 
minated by curved fangs containing a poison-duct. The 
Horse-shoe Crab uses its feet for prehension, and the 
thighs, or basal joints, of its legs to masticate the food 
and force it into the stomach. The first six pairs of legs 
in the Lobster and Crab are likewise appropriated to con- 
veying food into the mouth, the sixth being enormously 
developed, and furnished with powerful pincers, one of 
which serves as an anchor, enabling the creature to hold 
fast to some fixed object, 
while the other is an instru- 
ment for seizing or cutting 
‘its prey. Scorpions have a 
similar pair of claws for 
prehension, and also a pair 
Fia. 16. — One of the Fangs, or Perforated of small forceps for hold- 
ce oes ing the food in contact with 
the mouth. In their relatives, the Spiders, the claws are 
wanting, and the forceps end in a fang, or hook, which is 
perforated to convey venom.” 
The biting Insects, as Beetles and Locusts, have two 
