LIFE AND ELECTRICITY 23 



Before the seed can germinate its substance must he con- 

 tinually and adequately electrified. Why, then, cannot it 

 germinate while in its pod ? 



In the first place, the outer membrane, d, is in contact 

 both with the negative earth-lead and the positively charged 

 white pith, with the result that there is partial neutralisation 

 of charge ; I say partial because the seed-substance by 

 galvanometric test yields a feeble reaction showing weak 

 electrification, as against the strong electrification of a, a, 

 and c. Full provision is made for the protection of the seed 

 during development. The acid, moist layer, c, acts in much 

 the same way as the copper taping upon a telegraph or 

 telephone wire, or the lymph-space around a nerve-fibre, 

 in intercepting induced currents, so that so long as the 

 layer c is conductive the seed-substance cannot receive 

 sufiicient electrical stimulus to incite it to germination. 



To enable it, when mature, to reproduce its species, some 

 change must of necessity take place, and that change is a 

 very important one. 



When a pod falls from the tree and releases the seed 

 two things happen almost simultaneously. The outer 

 membrane d, dries and becomes a non-conductor, and the 

 layer, c, also dries up and forms a fibroid instead of a con- 

 ducting layer around the seed-substance. 



The subsequent electrical processes can now be readily 

 understood. The dry outer membrane, d, provides abso- 

 lute insulation for the seed until such time as it is buried 

 in the earth. It then, in contact with the damp soil, is 

 changed into a conductor and forms the outer coating of 

 tin foil, as it were, of a Leyden-jar. The, now, dielectric 

 layer, c, and the inner membrane, b, represent the insulating 

 material of the jar and the moist, acid seed-substance the 

 inner coating of tin foil. 



A diagram will be useful. 



F,^ /J 



.C.6 



