294 DARWINIANISM. 



and with quite as much reason as he might we not 

 use here, of the organic, Mr. Darwin's own words (sub- 

 stantially) of the inorganic, "It is sheer stupidity to 

 bring forward any such insoluble problems " ? 



Even such an insoluble problem is this of colour 

 generally ; as is most vividly suggested by what we are 

 told in Blackwood for April 1890, article "Animals, 

 Painted and Sculptured," by Mr. Frank E. Beddard, an 

 expert, a well-known official zoologist. " Colour in the 

 animal kingdom is due to two causes," he says, " either 

 to the presence of colouring matters, of pigments, or to 

 the presence of fine sculpturings which produces an 

 optical effect of a certain colour." Of pigments he gives 

 some curious examples, thus : 



" Its spines (those of the tree-porcupine of Brazil), which are 

 greatly concealed by the hair, are bright-yellow-coloured if the 

 yellow colour is of any use, why should it be so carefully covered 

 up? the yellow spines when washed with warm or even cold 

 water, become white if it is unintelligible how the creature got 

 its spines coloured in the first place, it is still more difficult to 

 understand how it is that the colour is not a ' fast ' one it almost 

 looks as if nature were playing a practical joke upon us. Another 

 example of a creature tinted with colours that ' run ' is the touraco, 

 and, according to one writer at any rate, the African trogoris. A 

 smart shower of rain is said to wash out the red colour from the 

 wings of these birds, and we can confirm the truth of this it is 

 probable that the variously - coloured pigments are simply waste 

 products, which happen, like the red exudation from the skin of 

 the hippopotamus to be coloured, temporarily stored up on the skin, 

 and ultimately got rid of. On this view we can perhaps understand 

 why the red of the touraco's feathers arid the yellow of the porcu- 

 pine's spines can be washed out so easily. Here birds and insects 

 have been generally referred to, while worms, and star fishes, and 

 cr.il >s, and such like, have been rather ignored. A congregation of 

 blue, purple, and red invertebrates, living four miles below the 

 surface of the sea, cannot reap much advantage from being im- 

 pressed by their neighbour's gaudy attire, even if they could see 

 it, but they cannot see it, for the very good reason that, for the 

 most part, they have no eyes, and if they had, it is too dark to see 



