COLOURS OF PLANTS. 227 



whose pods curl up and split open on the tree, dis- 

 playing the brilliant red seeds within. It is very hard 

 and glossy, and is said to be, as no 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 so get dis- 

 persed. If so it would be a case among plants analogous 

 to mimicry among animals an appearance of edibility 

 put on to deceive birds for the plant's benefit. Perhaps 

 it succeeds only with young and inexperienced birds, 

 and it would have a better chance of success, because 

 such deceptive appearances are very rare among plants. 



The smaller plants w r hose seeds simply drop upon the 

 ground, as in the grasses, sedges, composites, um- 

 belli ferae, &c., always have dry and obscurely- coloured 

 capsules and small brown seeds. Others whose seeds 

 are ejected by the bursting open of their capsules, as 

 with the oxalis and many of the caryophyllacese, scro- 

 phulariacese, &c., have their seeds very small and rarely 

 or never edible. 



It is to be remarked that most of the plants whose 

 large- seeded nuts cannot be eaten without destroying 

 their germinating power as the oaks, beeches, and 

 chestnuts are trees of large size which bear great 

 quantities of fruit, and that they are long lived and 

 have a wide geographical range. They belong to what 

 are called dominant groups, and are thus able to endure 

 having a large proportion of their seeds destroyed with 

 impunity. It is a suggestive fact that they are among 

 the most ancient of known dicotyledonous plants oaks 

 and beeches going back to the Cretaceous period with 

 little change of type, so that it is not improbable that 



Q 2 



