atjThor's abstract of this paper issued 

 by the bibliographic service, july 11 



THE PHYSIOLOGY OF THE NERVOUS SYSTEM OF 

 THE TUNICATE 



II. THE RELATION OF THE NERVE GANGLION TO THE HEART 



EDWARD C. DAY 



Department of Zoologij, University of Cincinnati 



CONTENTS 



Introduction 45 



Materials and method 46 



Normal beat of the heart 47 



Operations and their effect on the beat 49 



Recovery from operations 52 



Summary of results 53 



Discussion of data 54 



Tables 60 



INTRODUCTION 



In a previous paper (Day '19) the author showed that while 

 the ganglion of the tunicate exerts certain coordinating and 

 tonic effects upon its sensory reactions, they are not wholly 

 under the control of the ganglion. Since it is also an estab- 

 lished fact that the heart of the tunicate is capable of beating 

 not only independently of the nerve ganglion, but apart from 

 and independently of the body as well, the question arises as to 

 whether the ganglion dispatches accelerator or inhibitory im- 

 pulses to the heart, and whether it in any way augments or 

 diminishes the vigor of the rhythmical contractions, or whether 

 the heart is entirely unregulated by any ganglionic influence. 



It was hoped that a careful recording of the beat under varied 

 experimental conditions with the aid of a kymograph would 

 reveal whatever influence the ganglion might exert. 



45 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 34, NO. 1 



