56 
NATURE OF THE 
complex elaboration of its organs, which has constantly 
rendered it a great object of attention to the anatomist 
and physiologist. 
Dr. Roget, in his Bridgewater Treatise under the head 
of Cephalopoda, states “ that we now arrive at a highly 
interesting family of mollusca, denominated cephalopoda, 
and distinguished above all the preceding orders, by 
being endowed with a much more elaborate organiza- 
tion, and a far wider range of faculties. The cephalo- 
poda have been so named from the position of certain 
organs of progressive motion which are situated on the 
head, and like the tentacula of the polypus, surround 
the opening of the mouth. These feet or arms, or ten- 
tacula, if we choose to call them so, are long, slender, 
and flexible processes, exceedingly irritable and con- 
tractile in every part, and provided with numerous 
muscles, which are capable of moving and twisting them 
in all directions with extraordinary quickness and pre- 
cision; they are thus capable of being employed as 
instruments not only of progressive motion, but also of 
prehension. For this latter purpose they are in many 
species peculiarly well adapted, because, being perfectly 
flexible as well as highly muscular, they twine with ease 
round an object of any shape, and grasp it with prodi- 
gious force. In addition to these properties, they derive 
a remarkable power of adhesion to the surfaces of bodies 
from their being furnished with numerous suckers all 
along their inner sides. Each of these suckers is usually 
supported on a narrow neck or pedicle, and strengthened 
at its circumference by a ring of cartilage. Their internal 
