PDF - Wallace Online

vr COLOURS OF PLANTS 899is not carried farther is probably because it is not needed,these trees producing such vast quantities of fruit, that, howevermany are eaten, more than enough are always left toproduce young plants. In the case of the attractively colouredfruits, it is curious to observe how the seeds are always ofsuch a nature as to escape destruction when the fruit itself iseaten. They are generally very small and comparativelyhard, as in the strawberry, gooseberry, and fig;if a littlelarger, as in the grape, they are still harder and less eatable ;in the fruit of the rose or (hip) they are disagreeably hairy ;in the orange tribe excessively bitter. When the seeds arelarger, softer, and more eatable, they are protected by anexcessively hard and stony covering, as in the plum andpeach tribe or ; they are enclosed in a tough horny core, aswith crabs and apples. These last are much eaten by swine,and are probably crushed and swallowed without bruisingthe core or the seeds, which pass through their bodiesundigested. These fruits may also be swallowed by some ofthe larger frugivorous birds, just as nutmegs are swallowedby pigeons for the sake of the mace which encloses the nut,and which by its brilliant red colour is an attraction as soonas the fruit has split open, which it does upon the tree.There is, however, one curious case of an attractivelycoloured seed which has no soft eatable covering. The Abrusprecatoria, or " rosary bean," is a leguminous shrub or smalltree growing in many tropical countries, whose pods curl upand split open on the tree, displaying the brilliant red seedswithin. It isvery hard and glossy, and is said to be, asno doubt it is," very indigestible." It may be that birds,attracted by the bright colour of the seeds, swallow them,and that they pass through their bodies undigested, and soget dispersed. If so it would be a case among plants analogousto mimicry among animals an appearance of edibilityput on to deceive birds for the plant's benefit. Perhaps itsucceeds only with young and inexperienced birds, and itwould have a better chance of success, because such deceptiveappearances are very rare among plants.The smaller plants whose seeds simply drop upon theground, as in the grasses, sedges, composites, umbelliferae,etc., always have dry and obscurely coloured capsules and