THE STRUCTURE OF THE SEED 



37 



also rich in green pigment and highly electrified, while the 

 membrane to which I have referred, is white. If the green 

 pigment is chlorophyll it must be electrically as well as 

 optically influenced ; otherwise I am at a loss for an explana- 

 tion of the phenomenon, the embryo shell being in a state 

 of absolute darkness, as well as the membrane. 



We may now have a look at the walnut in its electrical 

 aspect, commencing with a longitudinal section of the nut 

 in its pod. 



^-~ 



Section of Walnut. 



a, cavity; 6, seed substance; c, positive moist pith ; d, non-conductiiig 

 dry fibre ; e, negative terminal ; /, negative tongue ; g, positive terminal. 



As in the case of the horse and edible chestnut, the hazel 

 nut and the acorn, the seed substance is only feebly electrified 

 and the secretion acid ; in this instance, mildly acid. The 

 negative terminal — the stalk — connects with the tongue- 

 like piece, /, and the negative system appears to be confined 

 to this and to terminate at the dry fibrous, semi-spatulate 

 point, A, which, with its wings, insulates it from the positive 

 part, c. 



/?._ 



-/ 



Wai,nut Shei,!, and Negative System. 



