212 COLOUR IN NATURE chap. 



have a scant fauna and flora are all dull of tint. 

 This has been explained on the usual assumption of 

 protective coloration, but it seems difficult to see 

 that any explanation is necessary beyond that of 

 the simple fact that in those situations the conditions 

 of life are relatively unfavourable, that therefore • 

 dominant or brightly coloured forms are not likely 

 to occur. 



2. Deep-sea Fishes. — With the colours of these 

 reef-fishes we may contrast the type of coloration 

 seen in deep-sea forms. These are usually remark- 

 able for their uniformity of colouring, bands, spots, or 

 stripes being rare. Dark brown or black colours 

 seem on the whole to predominate, and it is not 

 infrequent for the mouth and gill cavities to be very 

 darkly pigmented with black. After brown and 

 black colours come violet or yellowish tints, usually 

 dull-coloured, although a few examples are known 

 of deep-sea fishes showing considerable brilliancy of 

 tint. 



3. Temperate Fishes. — It is unnecessary to 

 describe the colours of the fishes found at moderate 

 depths in temperate waters. The silvery iridescence 

 of the lower surfaces of many, the frequency of dark 

 spots or stripes, the not uncommon occurrence of 

 red or orange pigments in the skin or muscle are 

 familiar to all. 



In general, fishes display considerable beauty of 

 colour, but usually of a somewhat fugitive type. 

 Under the most favourable conditions the beauty is 

 in large part lost during any process of preparing 

 the skins for mounting ; and it is probably to this 

 rather than to any other cause that the prevalent 



