UR. STARK'S EXPERIMENTS 55 



pike upon the trout, and the grampus upon the 

 salmon, are safely and rapidly cured. I have 

 caught trouts, particularly in the neighbourhood 

 where pike harbour, in various states of mutilation, 

 yet seemingly in good health and spirits ; from all 

 which I infer that their physical sufferings are less 

 than we suppose, and that the quiverings which 

 they exhibit when dying are rather of a galvanic 

 (which the change of colour seems to countenance) 

 than of a convulsive or very painful character. It 

 is, at least, comfortable for those who have been 

 accessary in early life to much apparent suffering, 

 to find out afterwards that the suffering was more 

 apparent than real.' 



" Sir David Brewster stated to the Society that 

 he had been led to consider this subject in con- 

 sequence of a correspondence with W. Scrope, 

 Esq., who had paid much attention to the change 

 of colour in fishes. Mr. Scrope was of opinion 

 that a real change of colour took place, if not 

 voluntarily, at least very quickly ; and he supported 

 his views by the following opinions of Mr. Yarrell 

 and Mr. Shaw : — 



" ' An interesting account (says Mr. Yarrell) of 

 some experiments made by Dr. Stark, was pub- 

 lished in Jamieson's Edinburgh Journal for 1830, 

 page 327. It shows that the colour of stickle- 

 backs, and some other small fishes, is influenced 

 not only by the colour of the earthenware or other 

 vessel in which they are kept, but also modified by 

 the quantity of light to which they are exposed ; 

 becoming pale when placed in a white vessel in 

 darkness, even for a comparatively short time, and 



