84 WITH HARD CHEEKS. 



there any mention made of the locality from Avliich it had 

 been derived. Dr. Stark observed that his Four-spined 

 Stickleback had all the varied colours of the other species of 

 the genus, except the bright red or scarlet sometimes found 

 in the males. Some experiments made by this gentleman — 

 an interesting account of which was published in Professor 

 Jameson''s Edinburgh Journal for 1880, page 327 — shows 

 that the colour of these and some other small fishes is influ- 

 enced, not only by the colour of the earthenware or other 

 vessel in which they were kept, but also modified by the 

 quantity of light to which they were exposed ; becoming pale 

 when placed in a white vessel in darkness even for a compa- 

 ratively 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 accom- 

 modating their colour to the ground or bottom of the waters 

 in which they are found. The final reason for this may be 

 traced to the protection such a power aifords to secure them 

 from the attacks of their enemies, and exhibits another beau- 

 tiful instance of the care displayed by Nature in the preser- 

 vation of all her species. Dr. Stark often observed that on 

 a flat sandy coast the flounders Avere coloured so very much 

 like the sand, that, unless they moved, it was impossible to 

 distinguish them from the bottom on which thev lav. 



The specimens sent me have four spines, placed at equal 

 distances from each, on the dorsal line, with one broad lateral 

 plate nearly hid by the pectoral fin, and forming an ascending 

 portion on each of the ventral plates. The fin-rays : — 



D. IV -I- 8 : r. 9 : V. 1 : A. 1 + 8 : C. 12. 



The colour has been already noticed. The figure is double 

 the natural size. 



