DK. staek's experiments. 53 



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 Avho have been accessary in early life to much 

 apjmrent 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 consequence of a cor- 

 respondence with W. Scrojje, 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 pubUshed 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 



E 3 



