THE RELATION BETWEEN SPECTRAL COLOR AND 

 STIMULATION IN THE LOWER ORGANISMS^ 



S. O. MAST 

 The Johns Hopkins University 



FOUR FIGURES 



CONTENTS 



Introduction 472 



Methods and materials 483 



Experimental observations 491 



Introduction 491 



Euglena viridis 492 



Euglena gracilis 497 



Euglena tripteris 499 



Euglena granulata 500 



Euglena minima 501 



Phacus triqueter 502 



Trachelomonas euchlora 502 



Chlamydomonas globulosa 503 



Gonium pectorale 505 



Pandorina morum 506 



Eudorina elegans 512 



Spondylomorum quaternarium 513 



Arenicola cristata (larvae) 515 



Lumbricus terrestris 517 



. Blowfly (larvae) 519 



Discussion 522 



Summary 524 



Bibliography 526 



^ Contribution from the Nela Research Laboratory, National Lamp Works 

 of the General Electric Company. 



The literary work connected with this paper was done at the Johns Hop- 

 kins University; the experimental work at the Nela Research Laboratory, 

 Cleveland, Ohio, during the summer of 1915 (July-September). 



It is a genuine pleasure to express my appreciation of the courtesies extended 

 on every hand by the director of this laboratory and his associates. Much 

 expert advice of the greatest importance, especially that concerning the manipu- 

 lation of electrical apparatus, was received from various members and the re- 

 sults obtained both in quantity and in quality are in no small measure directly 

 related to the generous interest taken in my work and to the unexcelled facilities 

 placed at my command. 



471 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 22, NO. 3 

 APRIL, 1917 



