336 EARL S. JOHNSTON 



The roots of potato sprouts showed a marked tendency to rot 

 when grown in nutrient solutions. 



Best growth was obtained from plants grown in a three-salt 

 solution where most of the osmotic pressure was due to calcium 

 nitrate. 



Plants of the Irish Cobbler variety showed a greater tendency 

 to form new tubers than those of the McCormick variety. 



