32 DICOTYLEDONS 



The seeds that had thus already begun to germinate would simply 

 die of thirst and it would be almost impossible for a plant to 

 reproduce itself by seeds. In the case of annual herbs, such as 

 Peas and Beans, etc., it would mean the extirpation of the genus 

 in a very short time; for annual herbs are not able to live 

 after flowering and fruiting. Another advantage of having hard, 

 •dry seeds is that animals, birds, and insects cannot destroy them 

 so readily as they could if they were soft. 



(b) We have noticed that tJie first part that comes out of the 

 germinating seed is the root. There is a reason for this. The 

 young plant must be fixed in the ground, when the hook-like stem 

 breaks through the surface of it. The side roots, issuing from 

 the main root, make the mooring so much the firmer. The wind 

 may now blow in whatever direction it will, it cannot overturn 

 the plant. The root has also other work to do. It must take 

 in water and nourishment Avhich is to be conveyed to the leaves 

 where it will be transformed into that condition in which it can 

 be used by the plant for the building up of new leaves. Now, 

 the root must necessarily grow before any other part can do so. 

 For then it will be ready for its functions and can at once send 

 up food to the leaves when they are formed. 



(c) The bud being extremely tender would suffer injury, if 

 it had to force its way up through the soil. So the thick, strong 

 stem bends in such a way that the bud remains below whilst it 

 raises the earth above it. 



(d) All the parts of the germinating seed are entirely colour- 

 less so long as they are within the coat of the seed and below 

 the surface of the earth. They become green, however, when they 

 come up to the light. It is the action of simlifjht ivJricJi pro- 

 duces the fjreen colour in the stems and leaves of the plants. 



(e) We know that the i)lants build up new parts from the 

 food prepared in the leaves. lUit whence does the germinating 

 seed take the materials necessary to form the root, the stem, and 

 the leaves, as it has no leaves to prepare its food? We shall 

 be in a position to give an answer to tliis question when we 

 examine the seed-leaves carefully. These leaves are hard and 

 full in the beginning, but gradually they become softer and softer 



