CLASS CEPHALOPODA. 73 



the sea. These suckers, numerous as they are, are entire- 

 ly under the control of the animal ; and each is furnished . 

 with a ring of horny hooks round its margin (fig. 31, C, 

 so that they constitute collectively a most efficient appa- 

 ratus for adhesion and for grasping purposes. The two 

 longer arms are known as the "tentacles" (fig. 3i> ^\0i 

 and they only carry suckers at their extremities, which 

 are expanded and club-shaped. 



If we separate the arms a little from one another, so as 

 to expose the front of the head, we see the opening of the 

 mouth, surrounded by the bases of the arms (fig. 31, D, 

 m) ; and within the mouth is a pair of strong jaws, of a 

 horny consistency, brown with white tips, and very like 

 the beak of a parrot, except that the undermost jaw is the 



longest. 



The only other point in the external anatomy of the 

 animal which needs mention, is a pecuKar tube which is 

 seen on the under surface of the head. (This is not visi- 

 ble in fig. 31, A, since this represents the upper surface 

 of the animal, but it is shown in fig. 31, D, /). This 

 tube is called the " funnel," and the animal has the power 

 of ejecting through it a stream or jet of water. By means 

 of this jet, by its reaction on the surrounding water, the 

 animal can propel itself, tail foremost, without the neces- 

 sity of using its fins. The " funnel " also serves other 

 purposes winch will appear hereafter. 



Returning now to the mouth, we may briefly examine 

 the internal structure of the animal. The mouth, with its 

 beak-like jaws, opens into a gullet, surrounding which we 

 find a ring of nervous matter (fig. 32, ?i), which represents 

 the brain of the higher animals, and which is protected by 

 a rudimentary skull. Besides the jaws, the mouth also 

 contains a tongue, the hinder portion of which is covered 

 with spines. The gullet leads into a stomach, from Avhich 

 proceeds an intestine, terminating at the bottom of the 

 " funnel." The funnel, therefore, serves to convey out of 

 the body the undigested portions of the food. There is 

 also a well-developed liver (fig. 32, I), which pours its 

 secretion into the intestine. Placed upon one side of the 



