DR. STARK'S EXPERIMENTS 57 



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, comfort- 

 able 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 conse- 

 quence 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 published 

 in Jamieson's Edinburgh Journal for 1830, page 327. 

 It shows that the colour of sticklebacks, 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 regaining their 

 natural colour when placed in the sun. From these 

 circumstances, observed also in some species of other 

 genera, Dr. Stark is led to infer that fishes possess, 

 to a certain extent, the power of accommodating 

 their colour to the ground or bottom of the waters 

 in which they are found. The final reason for this 



