CEPHALOPODA. 427 



tain gases or fluids are drawn into the interior, and thus aid 

 in the supply of nourishment for the growth of the animal. 

 The cell-wall appears to bear the same relation to the 

 future perfect animal, that the egg-shell of the chick does 

 to it ; it is, in fact, but an external covering to a certain 

 amount of gaseous and fluid matter, used for placing the 

 germ of life in a more favourable state for development, 

 assisted, as it is, by an increase of temperature, usually 

 the resultant of a chemical action, set up or once begun 

 in an organism and a medium. " The ovum destined to 

 become a new creature originates from a cell, enclosing 

 gemmules, from which its tissues are formed, and nutriment 

 is assimilated, and which eventually enables the animal to 

 successively renew its organs, through a series of meta- 

 morphoses that give it permanent conditions, not only 

 different, but even directly contrary to those which it had 

 primitively." 



" Oh, there are curious things of which men know 

 As yet but little ! secrets lying hid 

 Within all natural objects. Be they shells, 

 Which ocean flingeth forth from off her billows 

 On the low sand, or flowers, or trees, or grasses, 

 Covering the earth ; rich metals or bright ores, 

 Beneath the surface. He who fmdeth out 

 Those secret things hath a fair right to gladness : 

 For he hath well performed, and doth awake 

 Another note of praise on Nature's harp 

 To hymn her great Creator." 



Cephalopoda. Molluscous animals without a foot, with 

 a distinct head, and covered with fleshy arms, bearing 

 sucker-like discs. The Cuttles and Squids form the prin- 

 cipal groups of this class, only a few species of which are 

 found on our shores. These molluscs are the nearest 

 approach of all invertebrate animals to the vertebrate 

 forms ; and all the senses appear to be highly developed 

 in them. Their most characteristic peculiarity is, that 

 the front of the body, which forms a large head, carries 

 numerous fleshy arms, these are effective instruments for 

 the seizing and holding of the living prey on which they 

 feed; they are likewise used for crawling. One very 

 curious circumstance in the economy of the Cuttles, is 

 the power they possess of suddenly discharging a volume 

 of fluid of intense blackness, which is secreted in the ink- 

 bag. This fluid was used by the ancients for writing, and 



