126 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 



tissue at one end of the ribbon, a portion of the 

 latter would go into a spasm. The object of this 

 experiment was to ascertain how far into the 

 ribbon-shaped tissue the wave of spasm would 

 penetrate. As I had expected, different specimens 

 manifested considerable differences in this respect, 

 but in all cases the degree of penetration was 

 astonishingly great. For it was the exception to 

 find cases in which the wave of spasm failed to 

 penetrate from end to end of a spiral strip caused 

 by a section that had been carried twice round the 

 nectocalyx ; and this is very astonishing when we 

 remember that the ordinary contraction-waves, 

 whether originated by stimulation of the contractile 

 tissues or arising spontaneously from the point of 

 attachment of the marginal strip, usually failed to 

 penetrate further than a quarter of the way round. 

 Moreover, these waves of spasm will continue to 

 penetrate such a spiral strip even after the latter 

 has been submitted to a system of interdigitating 

 cuts of a very severe description. 



Now, we have here to deal with a class of facts 

 which physiologists will recognize as of a perfectly 

 novel character. Why it should be that the very 

 tenuous tracts of tissue which I have named should 

 have the property of responding even to a feeble 

 stimulus by issuing an impulse of a kind which 

 throws the contractile tissues into a spasm ; why it 

 should be that a spasm, when so originated, should 



respond at all) ; but each time the section crosses one of the 

 radial tubes, the whole bell in front of the section, and the whole 

 strip behind it, immediately go into a spasm. 



