Fruits and Seeds 13 



is small and likely to be easily damaged there is 

 generally a good deal of it there to make up for what is 

 lost. For instance the common henbane produces about 

 10,000 seeds on one plant every year, and it has been 

 calculated that if every one of these seeds became a 

 plant there would be enough henbane to cover the 

 earth's surface in three years. When the seed ger- 

 minates the young plant is at first unable to draw its 

 own food from the earth and the air as it will do latei 

 on. To make up for this some food which can be easily 

 absorbed is always put ready for it in the seed. Our 

 most nourishing vegetable foods, such as all kinds of 

 corn, beans, and nuts, to mention only a few of the 

 most important, are drawn from the supplies which 

 have been laid by in seeds. Sometimes, as in wheat 

 grains, the food lies all round the young plant, and 

 sometimes it is all contained in the two fleshy seed 

 leaves which, in the case of the bean for instance, fill up 

 the whole seed. From these cotyledons, as they are 

 called, the food is drawn as soon as the plant begins to 

 grow. The whole is covered with a strong skin which 

 protects the young plant, while still in the seed, from 

 any sudden change of temperature. This skin does its 

 work so well that some seeds are said to have been 

 kept for nearly fifty years, and have then sprouted 

 without being much the worse for it. The fact is that 

 while a plant is in the seed it is in a sleeping state. As 

 soon, however, as it is supplied with moisture, air, and 

 warmth, all of which conditions are necessary for its 

 growth, it begins to wake up. When this stage is once 

 reached the seedling will die if any of those conditions 

 are taken from it, even though it got on quite well 

 without them while in the sleeping state. 



