THE PHOSPHORESCENT ORGANS IN THE TOAD- 

 FISH, PORICHTHYS NOTATUS GIRARD. 



CHARLES WILSON GREENE, 

 Assistant Professor of Physiology, Leland Stanford Junior University. 



CONTENTS. ^^^3 



I. Introduction 667 



II. Distribution of the Phosphorescent Organs and the Lateral-Line Sense 



Organs 669 



1. Lines of Organs on the Body 670 



2. Organs of the Lower Jaw and Head 673 



III. Structure of the Phosphorescent Organs 677 



1. The Lens 677 



2. The Gland 678 



3. The Reflector 678 



4. The Pigment 679 



IV. Nerve Supply of the Phosphorescent Organs 679 



V. Orientation of the Organs with Reference to the Surface of the Body.. 6S0 



VI. Development of the Phosphorescent Organs 681 



VII. Function of the Phosphorescent Organs 684 



I. Introduction. 



Fishes described as possessing phosphorescent organs belong 

 almost without exception to the deep-sea fauna. They live at 

 depths where the light of the sun rarely if ever penetrates, and 

 this fact is supposed to account for the process of evolution 

 which has brought about the phylogenetic development of light- 

 producing organs. It lent interest, therefore, to the study of 

 phosphorescent organs in fishes when in 1889 a paper appeared, 

 describing phosphorescent organs in Porichthys, a shore fish. 

 The study of these organs was made on unfavorable material, 

 as the author states, and as the structures described were so 

 obviously different from phosphorescent organs in other fishes, 

 it seemed desirable to reinvestigate the question. 



