THE SEED. 



69 



The embryo being the rudimentary plant consists of an 

 axis and one or more leaves. The apex of the axis is called 

 the Plumule, its lower end the Badicle, its portion between 

 the plumule and the radicle the Gaulicle, and the leaves 

 bear the name of Cotyledons. 



The seed-coats usually consist of two layers ; namely, of 

 the exterior integument called the Testa which is thick and 

 often very hard, and of the interior one called the Tegmen 

 which is commonly thin and delicate. 



Seed-coats 



Parts op the seed- 



\\ 



Testa. 



Tegmen. 



i Radicle. 



f Embryo I Caliliole 

 . Kernels I 





Plumule. 

 Cotyledons. 



Albumen. 



Kinds op the Seed. — In some seeds, as those of the 

 Ayame and Omugi (Fig. 89), the embryo has only one 

 cotyledon ; in some, as those of the Asagao (Fig. 90) and 



Fig. 



Pig. 90. 



Fig. 91. 



i 



Fig. 89. — Monocotyle- 



donous seed of the 



Omugi. 



Fig. 90.— Dicotyle- 

 donous seed of 

 the Asagao. 



Pia. 91.— Polycotyle- 



donous seed of the 



Akamatsu. 



