1876 MEDUSA 23 



cases, but never being anything remarkable. So far, 

 then, the matter seems favourable to the nerve-plexus 

 theory. 



In another disc-shaped species of naked-eyed. 

 Medusae with a long polypite, which I have called 

 Tiaropsis indicans, from its habit of applying this long 

 polypite to any part of the bell which is being 

 injured, the localising function of the polypite is de- 

 stroyed as regards any area of bell-tissue between 

 which and. the polypite a circumferential section has 

 been introduced. In other words, the connections 

 between the bell and the polypite, on which locaHs- 

 ing function of the latter depends, are exclusively 

 radial. But not so the connections between the bell 

 and the polypite, which render it possible for the 

 one to be aware that something is wrong somewhere 

 in the other. For if the whole animal be cut into 

 a spiral with the polypite at one end, irritation of 

 the other end of the spiral, or any part of its length, 

 causes the polypite to sway about from side to side 

 trying to find the offending body. And here it is 

 important to observe that wherever a portion of one 

 of the radial tubes occurs in the course of the spiral, 

 irritation of that portion causes a much stronger re- 

 sponse on the part of the polypite than does irrita- 

 tion of any of the general bell-tissue, even though 

 this be situated much nearer to the polypite. This 

 seems to show that the nervous plexus, if present, 

 has its constituent fibres aggregated into trunks in 

 the course of the nutriment tubes. 



Thus far, then, I should be inchned to adopt the 

 nerve-plexus theory. But lastly, we come to another 



