40 GERMINATION 



The last drawing shows the nut with the positive pith, c, 

 removed ; the dark space on either side of the seed sub- 

 stance giving an idea of its extent. On the right may also 

 be seen a portion of the fibrous membrane in which it is 

 enclosed, and at the apex the remains of the flower. 



In conclusion, the careful student will not fail to note 

 that whereas in the horse and the edible chestnuts no traces 

 of the flower appear, their structure differs electrically from 

 that of the walnut and that the flower opening is in their 

 case unnecessary. 



