IH3RODU3TIQH 



Although the behavior and physiology of starfish and 

 other aohinoderas have been given the attention of many and eminent 

 naturalists, it was hoped that an intensive study of the problem of 

 coordination in the several speoies available would bring to light 

 some data, that might prove of interest to the physiologist and 

 general aoologist. 



The work was commanded in the autumn of 1917, but in 

 December was interrupted by fourteen month* s service in the army* 

 Between February 1919 and June 1920 I hive spent most of my free 

 time experimenting upon and observing the activities of starfish* 

 It would be quite impossible to set down my data in full, following 

 each experiment and observation out in detail, for reasons of space 

 alone* isy evidence, therefore, has undergone a rather severe select- 

 ive process* 



I wish here to express my thanks to Professor s, J* Holmes 

 under whose direction the following study has been made, for his 

 careful criticism and his many helpful suggestions* I am greatly 

 indebted to Professor W* K* Fisher, of the Hopkins Marine Station 

 of Stanford University, for his courtesy in putting the facilities of 

 his laboratory at my disposal, and for bis help in collecting and 

 keeping alive the material. He was also kind enough to detenoine the 

 speoies I worked upon* I wish also to express my thanks to Professors 

 S. S, Maxwell and T. 0* Burnett, of the Physiology department of the 

 University of California for their helpful advice* 



