THE STRUCTURE OF THE SEED 33 



illustration will serve to show the electrical connections, 

 although it is not a good example of the series method. 



The earth lead is direct to the cup upon which the acorn 

 is seated, and the contact upon the latter is clearly shown. 



Before I go any further it will be well to state exactly 

 what I mean by " static " charge ; the word " static " may 

 be taken too literally. 



Static electricity is said to be electricity at rest. Theoreti- 

 cally it is so. Practically it is not, it is only comparatively 

 at rest, because if it were really so it would argue perfection 

 of insulation and that is non-existent. It is really a matter 

 of relative resistance of parts of the circuit. If a Leyden-jar 

 is charged it does not retain its charge indefinitely. That it 

 does so at all is due to the high resistance of the path to 

 earth (the air), but it gradually loses charge by convection. 



In taking the insulation test of a submarine cable the 

 distant end is freed — by suspending it in the air — or sealed, 

 and the cable is then charged with a known electromotive 

 force for a certain number of seconds and the discharge 

 observed upon the scale of a galvanometer ; comparison 

 being made with a condenser of known capacity. The dis- 

 charge shows a loss of current, due to leakage through the 

 gutta-percha to the earth. Without leakage there would 

 be no circuit and where there is leakage there is electricity 

 in motion, although it is slow motion. Now there is always 

 leakage — to a greater or a lesser extent — where electricity 

 is concerned and electricity in motion is electrical energy. 

 Germination therefore calls, in my opinion, for an expendi- 

 ture of energy and not mere electrical pressure, which is 

 all that a purely static charge could exert. The resistance 

 of the inner membrane is certainly not greater than that of 

 gutta-percha and is probably much lower, while air is 

 present in the soil. The absolute insulation of the seed 



