PDF - Wallace Online

398 TROPICAL NATUREvery minute and are carried abroad by the wind, or they areviolently expelled and scattered by the bursting of the containingcapsules. Others are downy or winged, and arecarried long distances by the gentlest breeze, or they arehooked and stick to the fur of animals. But there is a largeclass of seeds which cannot be dispersed in either of theseways, and they are mostly contained in eatable fruits. Thesefruits are devoured by birds or beasts, and the hard seedspass through their stomachs undigested, and, owing probablyto the gentle heat and moisture to which they have been subjected,in a condition highly favourable for germination. Thedry fruits or capsules containing the first two classes of seedsare rarely, if ever, conspicuously coloured, whereas the eatablefruits almost invariably acquire a bright colour as they ripen,while at the same time they become soft and often full ofagreeable juices.Our red haws and hips, our black elderberries,our blue sloes and whortleberries, our white mistletoeand snowberry, and our orange sea-buckthorn, are examplesof the colour-sign of edibility ;and in every part of the worldthe same isphenomenon found. Many such fruits are poisonousto man and to some animals, but they are harmless toothers ;and there is probably nowhere a brightly colouredpulpy fruit which does not serve as food for some species ofbird or mammal.Protective Colours of FruitsThe nuts and other hard fruits of large forest-trees, thoughoften greedily eaten by animals, are not rendered attractiveto them by colour, because they are not intended to be eaten.This is evident, for the part eaten in these cases is the seeditself, the destruction of which must certainly be injurious tothe species. Mr. Grant Allen, in his ingenious work onPhysiological Esthetics, well observes that the colours of allsuch fruits are protective green when on the tree, and thushardly visible among the foliage, but turning brown as theyripen and fall on the ground, as filberts, chestnuts, walnuts,beechnuts, and many others. It is also to be noted thatmany of these aresome specially though imperfectly protected,by a prickly coat as in the chestnuts, or by a nauseouscovering as in the walnut ;and the reason why the protection