SUNLIGHT AND COLOURS. 51 



and body, being ultimately reduced to a pitiable 

 wretchedness of condition. These effects are 

 doubtless chiefly to be attributed to the absence 

 of light. Little though it may be generally 

 known, the flowers of various hues, the feathered 

 tribes of glorious plumage, and the bright and 

 beautiful among the insect tribes, and of those 

 which inhabit the great deep all owe their 

 many-coloured aspect to the influence of . light. 

 Is it not in the glowing atmosphere of the 

 Tropics that we find the most splendid flowers 

 and birds and insects ? There, where the 

 shadow of a cloud seldom flies over the bright 

 and burning plains, where no fogs and vapours 

 like those of our " distempered climate " interfere 

 with the power and brilliancy of the solar rays, 

 every object is in holiday attire, and gleams 

 with colours such as we should seek in vain in 

 our more temperate, but after all, more highly- 

 favoured region. Some remarks by Professor 

 Edward Forbes, in his Report on the Mollus- 

 cous and Radiate animals of the ^Egean Sea, 

 exhibit this very clearly : " The animals of 

 Testacea and the Radiata of the higher zones 

 are much more brilliantly coloured than those 

 of the lower, where they are usually white, 

 whatever the hue of the shell may be. Thus 

 the genus Trochus is an example of a group 

 of forms, mostly presenting the most brilliant 



