THE RELATION liETVVKEN LKJHT AND PIGMKNT-l^'ORMATION. 541 



The Relation between Light and Pigment-Forma- 

 tion in Crenilabrus and Hippolyte. 



By 



F. \¥. Oaiiible, F.R.S., 



Mason Professor of Zoology, University of Birmingham. 



With Plate 23. 



Contents. 



PAGE 



I. The Influence of Surroundings (algal backgrounds) on 



the Colour of Crenilabrus melops . • 542 



(1) Introductory . . ■ • .542 



(2) Pigments and Colour Changes . . • 544 



(3) The Influence of Daylight Reflected from Algal 



Backgrounds . • • • 546 



(4) The Influence of Light Transmitted through Alg* . 548 



(5) Note on the Coloration of Larval Gobies . . 550 



(6) Summary . . . ■ .551 

 II. The Colour-physiology of young Hippolyte vari an s . 552 



(1) Methods . . . • .553 



(2) Variability of the Larval Pigment . • 555 



III. (1) The Influence of Transmitted Monochromatic Light 



on the Formation of Pigments in Hippolyte 

 varians . . ■ • 



(2) The Influence of White Backgrounds and of Mono 

 chromatic Backgi=ounds in White Light . 



IV. The Food of Hippolyte as a possible Source of Pigment 

 V. Analysis of the Coloured Light Experiments 



VI. Summary of Results 

 VII. Experimental Tables (I— VI) 



Literature . . • • 



Explanation of Plate 



557 



560 

 561 

 564 

 572 

 574 

 582 

 583 



