344 



W. J. CROZIER 



was by this means (as well as by the movements of the body 

 wall) efficiently stirred as long as the piece continued to pulsate ; 

 local diffusion changes were thus avoided. One disadvantage of 

 this whole method lies in the fact that nothing could be done to 

 prevent the action of the solutions upon the cut surfaces along 

 the plane of amputation. The magnitude of this effect could 

 not be estimated. 



/iaCI.-'^an 



* *l/C/, ^^an 



30 



10 20 JO 40 50 60 70 80 SO 



Individual records illustrating the action of the single salt 

 solutions in which cloacal pulsation occurred are plotted in figure 

 30. Table 9 contains a summary of the results of these experi- 

 ments. With NH4CI and KCl, although the anal sphincters were 

 tightly closed, some irregular pulsation of the body wall usually 

 was evident for about the length of time indicated in table 9. 



The order of the disappearance of tactile irritability parallels 

 that of the stoppage of pulsation in these salt solutions. The 

 completeness of the correspondence argues for a close similarity 

 in the mechanisms of stimulation by internally and externally 

 generated agencies. 



