SECTION OF COVERED-EYED MEDUSiE. 101 



of a drop of spirit, the resulting waves of contraction 

 are almost sure to pass across the isthmus, even 

 though this has been exhausted in the manner just 

 described. 



Ganglia appearing to assert their Influence at a 

 Distance from their own Seat. 



Another fact, which I liave several times noticed 

 during my sections of Aurelia, also deserves to be 

 recorded. I have observed it under several modes 

 of section, but it will be only necessary to describe 

 one particular case. 



In the Aurelia of a portion of which the accom- 

 panying woodcut (p. 102) is a representation, seven 

 of the lithocysts were removed, while the remaining 

 one was almost entirely isolated from the general 

 contractile tissue by the incisions aa, 66, cc. The 

 lithocyst continued to animate the tissue-area xxxx, 

 and through tlie connecting passage y the con- 

 traction-waves spread over the remainder of the 

 sub-umbrella tissue zzzz. So far, of course, the facts 

 were normal ; but very frequently it was observed 

 that the contraction-waves did not start from the 

 lithocyst, or from the area xxxx, but from the point 

 o in the area zz. After this origination of the 

 contraction-waves from the point o had been ob- 

 served a great number of times, I removed the 

 lithocyst. Tiie effect was not only to prevent the 

 further origination of contraction- waves in the area 

 xxxx, but also to prevent their further origination 

 from the point o, the entire umbrella thus becom- 



