18 



Fruits and Seeds 



frequently as soon as the seed-vessel is really dried up 

 it splits open, in some cases with considerable violence, 

 and scatters the fruit on the ground. Seed-vessels that 

 split open are found in many different forms, some of 

 which are seen in the accompanying sketch (Fig. 11). The 

 pimpernel's seed-vessel and other similar ones have a 

 lid which opens when the seeds are ripe. In a third class 

 are those seed-vessels which like that of the poppy do not 

 open at all, but are provided with a row of small holes 

 near the top. The object of this arrangement is to 



(a) 



Fig. 12. 



(a) Acorn in shell ; (6) Acorn split in two longitudinally, 

 showing root and shoot. 



ensure that the seeds will fall some way from the parent 

 plant, where they are more likely to find room to grow. 

 Such a seed-vessel will only release the seeds if swayed 

 by a sudden knock or gust of wind, and this same blow 

 will throw the seeds some little distance. Berries, 

 although many-seeded, do not need any special arrange- 

 ment for separating the seeds, as the birds that feed on 

 them tear the fruit to pieces with their beaks. 



The second class of dry fruits, the one-seeded ones, 

 fall to the ground whole with their seeds inside them. 



