12 



CHAPTER III. 



HOW A PLANT GETS OUT OF THE SEED. 



By L. H. Pammki. 



The seed is the starting point of the individual in tl^at great 

 class o!: plmts kno\7n ?.s the Flowering Plants, represented by 

 such common types as the pea, bean, corn, rose and cabbage. 



I r, EAN. A common garden bean may be obtained at any time. 

 The seed is contained in a pod to which it is attached by a small 

 seed stalk. The seed is smooth, usually longer than broad. 

 There are many kinds of beans, the commonest bean is Avhite. 

 some beans are bluish bla.ck, others are spotted with brown, others 

 are yellowis!\ Yon will observe that the seed lies on one side. 

 Some beans are flattened on the two ends because they were 

 packed so very closely in the pod that they touched each other. 



You Vvill observe that the tv/o sides are much narrower than the 

 middle. Oi one side is a prominent spot callei the scar orliilum. 

 Fig. 3. This is where the seed stalk v/as attached to the seed On one 

 side ol the scar you Vvnll notice a very small hole somevx^hat sunken 



in the bean, the micropyle. On the other 

 end of the scar a pair of slightly elevat- 

 ed points. We Vvill novr soak the beans 

 in water for halt an hour. They have 

 greatly changed in their outline. The 

 i<iguie 3. beans are no longer smooth and even as 



Seed of bean, // hMum or ^ ^^.^.^ when We first examined them. 



seed scar, '" micrcpyle. " two 



processes ariUate. They are very much v>'rinkled. This 



wrinkled appearance is due to the water which they have taken up. 

 We can now pull off the white covering or shell as it is com- 

 monly called. This white covering is knoAvn as the seed-coat or 

 testa. The purpose of this coat is to protect the more delicate 

 parts of the plant within. We shall look out for the little plant tucked 

 away on the inside. We will now examine some beans which have 

 been in water twelve hours. The beans are larger; tliey liave taken 

 up much more water. The ridge near tiie small opening on one edge 

 of the seed scar is prominent. The seed coat should now be care- 

 fully removed. After the removal of the seed-coat tAvo large 



<i^ Figure 3. 



Bean seed in process of germination. Testa or seed- 

 coat broken, showing the cotvledons, ' "''. The hilum 

 or scar where the seed was attached shown at /'. The 

 small opening in the testa, micropyle shown at '". At 

 thebaseofthe radicle, the caulicle. 



