126 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
tissue at one end of the ribbon, a portion of the 
latter would go into aspasm. 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. 
