HOW SEEDS GBEMINATB 



15 



lower part with the brownish-green is a sheath, and 

 that the dark-green part is a new shoot that has 

 broken out of this sheath. In a 

 few days, this new shoot gives off a 

 broad leaf, and, a little further up, 

 another leaf. 



6. The veins in the leaves. 

 Take one of these wheat leaves 

 and hold it to the hght and you 

 will see that the veins all run 

 upwards, side by side. Take now a 

 leaf — a true leaf, of the French, 

 bean, and you will see that there is 

 a network of veins. Eemember 

 this difference carefully; for it is 

 one of the ways of telling whether 

 a plant belongs to the family of 

 plants with two seed-leaves or to 

 the family of plants with one seed- 

 leaf. All those that have the veins 

 running up side by side, as in the wheat leaf, 

 have but one seed-leaf ; all those that have a 

 network of veins, as in the leaf of the French 

 bean, have two seed-leaves. 



7. Tiie Roots. Coming back now to the 

 roots, we notice that the stout main root of 

 the French bean — the tap-root, has thrown 

 out slender side-roots (fig. 4). The tap-root has 

 grown quickly downwards to get out of reach 

 of drought, and the side-roots have been 

 thrown out to seek food, and to help to fix 

 the seedling in case of storm. They act like 

 the tent ropes that fasten down a tent. Pull 

 up one of the seedlings gently, and you will 



Wheat seed germina- 

 ting, showing the 

 hairy roots and the 

 second stage of the 

 fihoot. Compare with 

 flg.4. 



