48 



OSWALD SCHREINER AND J. J. SKINNER 



Growth in cultures containing no nitrate, with and without nucleic 



acid 



Table I gives the growth of the two sets of cultures comprising 

 the series of cultures containing no nitrates, but containing mix- 

 tures of potash and phosphate, varying in 10 per cent stages, 

 the total concentration being 80 parts per million of P2O5 + K2O 

 in each culture. In the fifth column are given the weights of 

 the cultures without nucleic acid, and in the last column the 

 weights of the cultures where nucleic acid was present. It is 

 apparent from these figures that the nucleic acid has caused a 

 considerable increase in growth. This is true in each of the 

 eleven cultures. For instance, in culture No. 37, which has 16 

 parts per million of phosphate and 64 parts per million of potash, 

 the growth without nucleic acid is 1.870 grams, and with nucleic 

 acid 3.520 grams. Culture No. 16 which is composed of equal 

 parts of phosphate and potash, produced 1.490 grams green 

 weight when nucleic acid was absent and 3.440 grams when the 

 nucleic acid was present in the solution. The growth in culture 

 No. 4, which is composed of 64 parts per million of phosphate 

 and 16 parts per million of potash, was 1.378 grams without 

 nucleic acid and 2.528 grams with nucleic acid. The total growth 



TABLE I 



Effect of nucleic acid on growth in culture solutions containing no nitrate 



CULTURE NO. 



FERTILIZER INGREDIENTS IN CULTUKE 

 SOLUTIONS 



GREEN WEIGHT OF CULTURE 



PjOs 



NHj 



KsO 



Without nucleic 

 acid 



With 100 p.p.m. 

 nucleic acid 







p.p.m. 



p.p.m. 



grams 



grams 



56 



0 



0 



80 



1.599 



3.090 



46 



8 



0 



72 



1.770 



3.040 



37 



16 



0 



64 



1.870 



3.520 



29 



24 



0 



56 



1.859 



3.100 



22 



32 



0 



48 



1.578 



3.000 



16 



40 



0 



40 



1.490 



3.440 



11 



48 



0 



32 



1.890 



2.750 



7 



56 



0 



24 



1.520 



2.800 



4 



64 



0 



16 



1.378 



2.528 



2 



72 



0 



8 



1.428 



1.859 



1 



80 



0 



0 



0.859 



0.970 



