344 



J. M. D. OLMSTED 



came feebler and finally (after three minutes) ceased. When 

 the animal was returned to normal sea-water pulsation was not 

 resumed. 



filf KC1 also caused the intestine to contract greatly. No 

 pulsations at all could be detected, nor did it resume pulsation 

 when returned to normal sea-water. 



Time for 10 

 pulsations 

 in seconds 



15 



20 



25 



30 



35 



40 



Temperature 



Fig. 2 Ordinates indicate time, in seconds, for 10 pulsations of excised pieces 

 of intestine of Synaptula; abcissae indicate temperature, centigrade. Different 

 symbols indicate different individuals from which the pieces of intestine were 

 taken. 



