238 PLANT PHYSIOLOGY 



from without will effect chemical and physical changes 

 within it. These changes, whether in the living protoplasm 

 itself or in its lifeless contents, cannot be without influence 

 upon the protoplasm itself. 



According to Loeb* " probably all electrical effects on 

 living things are only indirect. What we call electrical 

 effects are really due only to the chemical and molecular 

 action of the ions or the compounds formed from these" 

 set free in the living cells, or in the living organism, by 

 electrical force. Such an hypothesis as this is certainly com- 

 prehensive enough. Protoplasmic tensions and the strength 

 of the protoplasmic structure would surely vary with the 

 chemical and physical rearrangements taking place in the 

 dissolved salts of the cell-sap throughout the living cell. 



In spite of considerable experimental study of the possible 

 influence of electricity upon the rate and amount of growth 

 no general statement regarding it is now possible. Some 

 authors f claim that plants screened from atmospheric 

 electricity are smaller than plants grown under otherwise 

 similar conditions. Others J assert that increasing the at- 

 mospheric electricity by discharges from wires strung above 

 the plants, increases both the growth and the yield. The 

 eminent German agricultural physicist, Wollny, having 

 critically re-examined the subject, denies both claims. We 

 may, therefore, safety leave this question to the sanguine 

 students of applied botany, only hoping that the farmer 

 will not be led to cumber the ground and mar the land- 

 scape with unsightly screens of telegraph wire. 



* Loeb, J. Zur Theorie des Galvanotropismus. Archiv. f. d. ges. Physio- 

 logic, Bd. 67, 1*97. 



t Grandeau, L. De Finfluence de 1'electricite atmospherique sur la nutri- 

 tion des vegetaux. Ann. de Chem. et de Physique., T. XVI., 1879. Aloi, 

 .A. DelP influenza dell' elettricita atmospherica sulla vegetazione delle 

 piante. Bull. Soc. Bot. Italiana, 1895. 



t Lemstrom, S. Om elektricitens inflytande p& vaxterna. Helsingfors, 

 1890. Abstract by Bailey in Trans. Mass. Hortic. Soc., 1894. Also Elec- 

 tricultur. Erhohung der Ernteertrage aller Culturpflanzen durch elek- 

 trische Behandlung. f bers. von Pringsheim. Berlin, 1902. 



Wollny, E. Elektrisch > Culturversuche. Forsch. a. d. Gebiete d. 

 Agrik.-Physik., Bd. XVI. ? 1893. 



