THE BOOK OF NATURE STUDY 



splitting it into three pieces. It grows downwards, forming the 

 primary root and giving off lateral branches. 



2. The first thing to be observed above the soil is a structure 

 in the form of an arch. This is the portion of the skin below 

 the cotyledons, called the hypocotyledonary stem, or hypocotyl. 

 During the first stages of germination the cotyledons are busy 

 absorbing food from the mealy endosperm in which they are 



enfolded, and handing it on to 

 the growing seedling. 



3. The hypocotyledonary 

 stem next straightens itself, 

 sometimes making a revolution, 

 as shown in Fig. i, at the bent 

 portion. The two cotyledons 

 are still folded in the nut. 



4. Then the nut falls off, 

 and this is the moment to 

 observe the folding of the 

 cotyledons before they expand. 

 As soon as they spread them- 

 selves out they become green. 



FIG. i. Seedlings of buckwheat. A, Section The plumule situated between 

 of nut of buckwheat; pr, outer coat; them is at first very minute, 



radicle; /, plumule : ; *, b t j t SQOn wg rige 



endosperm. B, Seedling of buckwheat 



with outer coat ; pr, with coat still on. 

 C, Seedling, with outer coat off and coty- 

 ledons folded. D, Seedling with coty- 

 ledons, c, spread out. 



to the stem and foliage leaves. 



STAGES TO BE OBSERVED 

 IN GERMINATING SEEDS. In 

 watching the germination of seeds as just described in the buck- 

 wheat, the behaviour of the cotyledons, the elongation of the 

 radicle, and then the development of the plumule should be 

 noted. Observation of several typical seeds will show 



1. That germination is a much slower process in some than 

 in others. 



2. That the cotyledons behave very differently in different 

 cases. Sometimes they remain underground, the young plant 

 living for a time on the food contained in them. In other cases 

 they soon appear above the ground, and begin to make food for 



