SECTION OF COVERED-EYED MEDUS.E. 



03 



Or,ad()pting again thegraphic method ofstateiuent, 

 these vai'iations may be represented as follows : — 

 26° 



32° 



42 



65° 



75° 



85° 



One second ... ^^_^^^^^_^^^ 



Fig. 16. 



Submitting a contractile strip to slight strains has 

 also the effect of retarding the rate of the waves 

 while they pass through the portions of the strip 

 which have been submitted to strain. The method 

 of straining which I adopted was to pass my finger 

 below the strip, and then, by raising my hand, to 

 bring a portion of the strip slightly above the level 

 of the water. The in i table or contractile surface 

 was kept uppermost, and therefore suffered a gentle 

 strain ; for the weight of the tissue on either side 

 of the finger made the upper surface somewhat 

 convex. By passing the finger all the way along 



