236 



THE OCEAN WORLD. 



they are conical tubes, closed on all parts except at the point where 

 the tentacle is attached to the disk. Their cavity is filled with the 

 granulous liquid already mentioned. On the under surface of the 

 disk, and to the inside of these tentacles, the polyps and fishing-lines 

 are attached. 



The anterior part of the polyp is formed of a glass-like substance, 

 which changes its form in the most varied and surprising manner. It 

 bears a roundish mouth at its summit. In its posterior part the 

 polyp presents a straight hollow stem, of reddish colour ; but near to 



Fig. 96. 1 J . hydrostatica, with a portion of the disk, three polyps, and reproductive clusters attached. 



this red stem we find a thick tuft of cylindrical appendages, from the 

 middle of which springs the extensible and contractile filaments 

 which Yogt calls the fishing-lines (fil pecheur), and of which he has 

 given the following very strange account : 



" Each of these appendages consists of an assemblage of cylindrical 

 tubes somewhat resembling and analogous to a filament of confervae. 

 All these tubes are traversed by a continuous canal, which originates 

 in the internal cavity of the stem of the polyp. Each fragment of 

 the line is capable of a prodigious extent of elongation and contrac- 

 tion ; but where completely drawn back the pieces fold themselves up 



