154 



BOTANICAL GAZETTE 



[august 



there being no nitrate in the solutions; the concentration was 

 80 ppm. of P 2 5 +K 2 in each culture. To one set of cultures was 

 added 50 ppm. of creatinine. In the fifth column are given the 

 green weights of the cultures without creatinine, and in the last 

 column are given the weights of the cultures with creatinine. It 

 is apparent from these figures that the creatinine has caused a 



\ , 





Fig. i. — Wheat plants growing in culture solutions containing various propor- 

 tions of potash and phosphate (with no nitrates) without (a) and with (b) creatinine 



considerable increase in growth. 



true 



of the 11 



cultures. The total growth of the eleven cultures, without 

 creatinine, was 16.674 grams against 22.682 grams for the 

 cultures with creatinine. This is an increase of 36 per cent in 

 the creatinine cultures. 



The effect of creatinine in cultures with no nitrogen are shown 

 in the plants in fig. 1. Cultures marked with the same number, 

 for instance 1a and 16, have similar fertilizer ratios. The cultures 

 marked a have no creatinine, the numbers with the letter b have 



