84 ELEMENTAET BIOLOGY. [VIII. 



f.' The seeds. 

 1. Soak some dried beans in water for twenty-four hours ; 

 they will slightly swell up and be more readily ex- 

 amined than when dry. 



a. Note the black patch on one end of the bean, 

 marking where the stalk (funiculus) which fixed 

 it in the pod was attached to it. 



h. Having wiped all moisture off the bean gently 

 press it while observing that part of the black 

 patch which is next its broader end: close to 

 the patch a minute drop of fluid will be observed 

 to be pressed out through a small opening, the 

 micropyle. 



c. Carefully peel off the outer coat (testa) of the 

 seed: the two large fleshy cotyledons will be 

 laid bare. 



d. Joining the cotyledons together will be found 

 the rest of the embryo : it consists of a conical 

 part (the radicle) lying outside the cotyledons, 

 with its apex directed towards the point where 

 the micropyle was ; and of the rudiments of 

 the stem and leaves (plumule) lying between 

 the cotyledons. 



g. The process of fertilization. 



This is difficult to follow in the bean; but by using 

 diflferent plants for the observation of its various stages 

 it is fairly easy to observe all its more important steps. 



1. A plant well adapted for seeing the penetration of 

 the pollen-tube into the stigma and style is the 

 Evening Primrose ( CEnothera biennis). 



Detach the style from the flower and hold the club- 

 shaped stigma between the finger and thumb of the 



