COLOURS OF FRUITS AND SEEDS 265 



Dry dehiscent fruits, capsules follicles, etc., are 

 usually of a dull brown or yellowish colour, and so 

 are usually the seeds they contain, but fleshy fruits 

 are generally when ripe, highly coloured red, yellow, 

 purple or black. The mango, cashew fruit, jujube 

 (ZIZYPHUS), pomegranate, apple, grape, are common 

 instances of this. Some of these have also green- 

 fruited varieties, more especially cultivated plants, e.g. 

 green grapes, but among wild plants, fleshy fruits 

 drupes and berries are much more commonly coloured 

 in such a way as to be very conspicuous against the 

 green foliage. In most cases, too, the colour develops 

 as the fruit ripens, only becoming conspicuous, whether 

 red, yellow, purple or black, when quite ripe. This 

 is just the opposite to what happens with dry fruits 

 and their seeds. While they are on the plant capsules 

 are, like unripe fleshy fruits, green and hidden away 

 among the leaves, but by the time the seeds have 

 ripened, they are brown or black and though conspicuous 

 perhaps on the tree, their contents, the seeds, being 

 now of a dull brown or black colour, are almost in- 

 visible against the brown soil on to which they fall. 



For this difference there must be a reason, and we 

 find the reason lies, as in the case of flowers, on 

 the inter-dependence of animals and plants. Seeds 

 being, as we saw in chapter v, packed full of highly 

 concentrated foodstuffs, are much sought after by 

 animals, and if it were not for the inconspicuous 

 colouration of the unripe pods on the plant, and of 

 the ripe seeds after they have fallen to the ground, 

 would soon be eaten by birds, squirrels, rats and 

 larger creatures. It is to increase, therefore, the 



