Vol. XXXVIII. April, 1920. No. 4. 



BIOLOGICAL BULLETIN 



LIGHT PRODUCTION IN CEPHALOPODS, II. 



AN INTRODUCTORY SURVEY. 

 S. STILLMAN BERRY, 



REDLANDS, CALIFORNIA. 



CONTENTS. 



PAGE 



5. Color and Intensity of Light .............................. 



6. Distribution of Photophores on Animal ................. i?4 



On Eyeball ............................................... *75 



In General Integument of Body ............................. i?6 



On Mantle ............................................ i?6 



On Head ................................... * 76 



On Arms ................................... z 7 



On Funnel ......................... : 77 



Around Eye-openings ................ i?T 



On Fins ............................... Z 77 



In Arms ........................... : 79 



In Tentacles ........................ : 8o 



Intrapallial ................... l8 



Anal ................ l81 



Branchial ...................... . . 181 



Gastric .................. . . 181 



Axial ........................ l81 



At Tip of Body ............... l82 



7. Structure of Photogenic Organs .... l8 3 



Diversity ..................... l8 4 



Component Structures .............. l8 5 



Duplex Organs ................. l8 5 



8. Polymorphic Nature of Photogenic Organs. . 186 



Genera with Isomorphic Photophores. . I 8 7 



Genera with Dimorphic Photophores ............. l8 7 



Genera with Trimorphic Photophores. . l8 7 



Genera with Polymorphic Photophores. * 8 7 



9. Systematic Significance of Photogenic Organs. . . 189 



10. Probable Polyphyletic Origin of Photogenic Organs. 190 



11. Concluding Note ....... I 9 I 



12. Summary ................... 



13. Literature ............. .................... : 93 



171 



