COLOURS OF PLANTS. 225 



ways, and they are mostly contained in eatable fruits. 

 These fruits are devoured by birds or beasts, and the 

 hard seeds pass through their stomachs undigested, and, 

 owing probably to the gentle heat and moisture to which 

 they have been subjected, in a condition highly favourable 

 for germination* The dry fruits or capsules containing 

 the first two classes of seeds are rarely, if ever, conspicu- 

 ously coloured ; whereas the eatable fruits almost in- 

 variably acquire a bright colour as they ripen, while at 

 the same time they become soft and often full of agreeable 

 juices. Our red haws and hips, our black elderberries, 

 our blue sloes, and whortleberries, our white mistletoe 

 and snowberry, and our orange sea-buckthorn, are 

 examples of the colour-sign of edibility ; and in every 

 part of the world the same phenomenon is found. Many 

 such fruits are poisonous to man and to some animals, 

 but they are harmless to others ; and there is probably 

 nowhere a brightly-coloured pulpy fruit which does not 

 serve as food for some species of bird or mammal. 



Protective Colours of Fruits. The nuts and other 

 hard fruits of large forest-trees, though often greedily 

 eaten by animals, are not rendered attractive to them 

 by colour, because they are not intended to be eaten. 

 This is evident ; for the part eaten in these cases is 

 the seed itself, the destruction of which must certainly 

 be injurious to the species. Mr. Grant Allen, in 

 his ingenious work on Physiological ^Esthetics, well 

 observes that the colours of all such fruits are protective 

 green when on the tree, and thus hardly visible among 

 the foliage, but turning brown as they ripen, and fall 

 on the ground, as filberts, chestnuts, walnuts, beech- 

 nuts, and many others. It is also to be noted that 



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