PLATE 8 



EXPLANATION OF FIGURES 



Views of specimen no. 4:/, after seven days on present background (condition 

 of rest) ; g, same, when preparing to swim; h, after one day on present background; 

 i, after three days on a background of gray, of a shade approximately matching 

 that produced on a color-wheel by the use of two parts of black and one of white. 

 (The harmony between the fish and the bottom was really much greater than would 

 seem to be the case from this photograph, which has made the fish seem darker). 



Specimen no. 5: view inserted to show a particularly striking gravel pattern 

 (taken after eight days). (There are in reality a few particles of gravel on the back 

 of the fish). 



494 



