NERVOUS SYSTEM OF THE TUNICATE 



325 



PROTOCOL ^—Continued 



h. Four hours later all of the amputated pieces were responsive, 

 and the amputated incurrent siphons 8A and 9A also exhibited 

 rhythmical automatic contractions. 



c. The latent period of response was lengthened as a result of 

 the operation. 



d. 9A, the piece with the ganglion included, gave visible 

 evidence of regenerating a new siphon in the center of the de- 

 generating amputated one. 



e. B showed little progress in the regeneration of the lost 

 parts for the same length of time. 



2. Experiments with amputated siphon 8 A 



a. When the amputated piece was stimulated at its proximal 

 or cut end, the impulse traveled distally and elicited a response 

 first at the margin. This response was of two orders depending 

 on the strength of stimulus: first, a local puckering in of one or 

 two of the lip-lobes, and, second, a constriction of the neck 

 region just proximal to the margin, followed by a pursing of the 

 whole distal end. These responses are shown by diagrams 25 

 and 24, respectively, in figure 5. The asterisk indicates the 

 point stimulated. 



