16,6 Espino: Salt Requirements of Young Rice Plants 523 
magnesium salt should be four or five times as great as that 
of any one of the others. The tolerance of these plants for 
magnesium sulphate is especially remarkable. 
9. The results of these experiments led to the conclusion that 
good growth of tops was generally accompanied by good growth 
of roots, a feature with regard to which these plants seem to 
differ from wheat. 
10. Dry yield of tops, dry yield of roots, green weight of 
tops, and the amount of water absorbed during the three-week 
period, all appear to furnish valuable criteria for comparing 
growth in these different solutions, and all four criteria are 
in good general agreement. 
