THE STRUCTURE OF THE SEED 39 



by the Great Electrician to safeguard it from the possibility 

 of premature germination and decay. This is achieved by 

 balancing the negative and positive electrifications and 

 providing the seed substance with a tough highly resistant, 

 air-tight envelope or membrane. When, however, the nut 

 is discharged from the pod and buried in the earth, the shell, 

 and the pith within it become negatively electrified and so 

 the conductive seed substance in its insulating membrane 

 obtains by induction the continuous electrical charge 

 without which germination could not proceed. 



As the inner membrane of the pod, together with the 

 middle layer, is markedly acid and is connected electrically 

 with the remains of the flower we can see in what manner 

 positive charge is conveyed to the acidulated pith, c, and 

 divine the purpose and meaning of the cavity, a, with its 

 non-conducting fibrous lining. 



The stalk is somewhat remarkable for the comparatively 

 large sectional area of the conductor. 



In a specimen before me the section has an outside dia- 

 meter of 3/16ths-inch, the conductor being stained with 

 green pigment, and an inside diameter of l/16th-inch, 

 exactly centred. It, in fact, presents the appearance of a 

 section of a heavily insulated metallic conductor ; the 

 material surrounding the earth-lead being fibroid in character 

 and darker in colour. 



In regard to what I have termed a " repair outfit " lost 

 insulation is partly, if not fully regained by the exudation 

 of wax upon the cut surfaces — a feature it possesses in 

 common with other nuts — while long life is ensured to the 

 seed substance by an ample liquid content and its tough 

 air-tight membranous envelope. 



Section op Walnut. — With positive pith, c, removed. 



