56 STRICTLY INCOG. 



colouring of the animals is uniform too. Where it is 

 slightly diversified from point to point, as in the sands of 

 the desert, the animals that imitate it are speckled or 

 diversified with various soft neutral tints. All the birds, 

 reptiles, and insects of Sahara, says Canon Tristram, copy 

 closely the grey or isabelline colour of the boundless sands 

 that stretch around them. Lord George Campbell, in his 

 amusing ' Log Letters from the " Challenger," ' mentions a 

 butterfly on the shore at Amboyna which looked exactly 

 like a bit of the beach, until it spread its wings and 

 fluttered away gaily to leeward. Soles and other flat-fish 

 similarly resemble the sands or banks on which they lie, 

 and accommodate themselves specifically to the particular 

 colour of their special bottom. Thus the flounder imitates 

 the muddy bars at the mouths of rivers, where he loves to 

 half bury himself in the congenial ooze ; the sole, who 

 rather affects clean hard sand-banks, is simply sandy and 

 speckled with grey ; the plaice, who goes in by preference for 

 a bed of mixed pebbles, has red and yellow spots scattered 

 up and down irregularly among the brown, to look as much 

 as possible like agates and carnelians : the brill, who hugs 

 a still rougher ledge, has gone so far as to acquire raised 

 lumps or tubercles on his upper surface, which make him 

 seem like a mere bit of the shingle-strewn rock on which 

 he reposes. In short, where the environment is most uni- 

 form the colouring follows suit : just in proportion as the 

 environment varies from place to place, the colouring must 

 vary in order to simulate it. There is a deep biological joy 

 in the term ' environment ' ; it almost rivals the well-known 

 consolatory properties of that sweet word ' Mesopotamia.' 

 ' Surroundings,' perhaps, would equally well express the 

 meaning, but then, as Mr. Wordsworth justly observes, 

 4 the difference to me ! ' 



Between England and the West Indies, about the time 



