12 Plants mtd their Ways in South Africa 



The peg is an odd little body. It is made for a purpose, 

 and grows only where it is needed. Sometimes the stem below 

 the peg grows too rapidly, or the seed coat is not held firmly 

 enough by the soil. Then the peg fails to hold the seed coat 

 in place and the plant has to get out as best it can. Do 

 such seedlings look as thrifty as others ? In Fig. 1 7 the peg 

 has done its work, and the coat has been left underground. 



Why has the cotyledon of the mealie not made its appear- 

 ance ? It remains down where the supply of food was stored, 

 which it has been absorbing and passing on to the plumule 

 and radicle. By the time these parts are able to make their 



Fig. 17. — Calabas. The 

 peg has done its work 

 for the little calabas 

 plant. 



Fig. 18. — Germinating 

 embryo of Zea tnais. 

 c, cotyledon ; r, ra- 

 dicle ; sr, first side 

 shoots growing from 

 stem. 



Fig. ig. — Germinating bean seeds. 

 a and b with one cotyledon 

 removed. 



own food the seed will feel quite soft. If you cut a seed 

 through the centre from front to back, and look at it with a 

 hand lens, you can see the little channels through which the 

 food passes. The radicle was protected in the seed by a little 

 pocket, as was the leaf. The cap does not grow as much as 

 the leaf-cap does, and the radicle soon pushes through it. 



In the Indian corn the first side roots come from the stem 

 just above the cotyledon. They are a part of the embryo. In 

 the pumpkin they come from the radicle which forms the tap 

 root; they are not formed until after the root begins to grow. 



