162 Transactions of the Society. 



I have referred to other eases, as, for instance, that of the 

 Geraniums, in my previous Address. 



Hairy seeds have already been mentioned under the head of 

 Dispersal, and the same applies to seeds with spines. 



In many cases, perhaps, it may be said that seeds are smooth 

 simply because there is no reason why they should be otherwise. 

 In cases, however, where seeds are thrown, as, for instance, out of 

 capsules, it is an advantage for them to be small, heavy, and perhaps 

 smooth.* 



When, however, they are only ejected so as to come under the 

 action of air currents, and the intention is that they should be 

 wafted by the wind, it is an advantage to be large and light. The 

 larger they are, the greater surface is exposed to the current of 

 air : the lighter they are, the longer they will be before they fall. 

 The roughened surface in such cases is also useful in anchoring the 

 seeds to the damp ground. 



Protection. — The protection of seeds has been incidentally 

 referred to, but must be directly mentioned. It is of the utmost 

 importance of course to the plant, and all the more as the 

 nutritious property of seeds render them specially tempting to 

 animals, and to vegetable parasites. In many cases, indeed, as in 

 Hazel nuts, Walnuts, Peas, etc., the many are sacrificed to the 

 few — the few being sufficient for the preservation of the race. 



Immature seeds and fruits are often protected by hardness or 

 bitterness, by resin or gum. When, on the contrary, they are 

 ripe, and their dispersal is to be effected by animals, they often be- 

 come sugary and well flavoured, and sweet-scented. When unripe, 

 moreover, they are inconspicuous. In other cases the unripe 

 seeds are protected by thick hard envelopes, as in the Beech and 

 Chestnut, which do not open till the seeds are ripe. 



But though the seeds require to be protected by a hard or 

 tough envelope, it must not be too much so. Thus the Beechnut 

 is protected by a fairly strong testa, but not too strong to make 

 them inaccessible to squirrels or mice. On the other hand, in the 

 nearly allied Hornbeam, when the seeds are carried by wind, it 

 would be a loss if any were eaten, and the testa is much harder 

 and stony. 



Other characters. — There are, indeed, many other points to be 

 considered with reference to fruits and seeds. 



* Since this was delivered, Sir Ralph Payne-Gallwey has contributed to ' The 

 Times ' (March 16, 1909) a very interesting series of experiments on the flight of 

 golf-balls. He determined the flight of a perfectly smooth ball, and then found 

 to his surprise that if he nicked the ball slightly with the point. of a knife, 

 spacing the small raised nicks about one-third of an inch apart . . . the ball flew 

 splendidly, and about twice as far. He suggests " a ball with slightly raised 

 lines intersecting its surface with spaces between the lines . . . which would 

 somewhat resemble in pattern the network on the outside of a melon." This 

 closely agrees with, and may throw light on, the reticulated surface of so many 

 seeds which are jerked out of a capsule. 



