PLATE III. 



I-IGMKNTATION OF THE LOWER SIDE OF A 



FLOUNDER (PLEURONECTES FLESUS) WHICH 

 WAS EXPOSED TO DAYLIGHT REFLECTED 

 FROM A MIRROR, FROM SEPT. 1890 JO 

 NOV. 1891. THE SPECIMEN WAS ABOUT SIX 

 MONTHS OLD AT THE BEGINNING OF THE 

 EXPERIMENT, AND THEN HAD NO PIGMENT 

 'ON THE LOWER SIDE. REPRODUCED BY 

 PERMISSION OF THE ROYAL SOCIETY FROM 

 PHIL. TRANS. 1893. B. 



