X Journal of Agricultural Research voi. xvi 



Page 

 Fig. 3. Graphs showing the hydrogen-ion concentration of wheat extract on 



titration to Ph 9-3 6 



4. Graphs showing the production of amino nitrogen at different 



temperatures 10 



5. Graphs showing the total phosphorus in wheat extract at different 



periods of extraction and at different temperatures la 



6. Graphs showing the inorganic phosphorus in wheat extract at different 



periods of extraction and at different temperatures 12 



Ash Absorption by Spinach prom Concentrated Soil Solutions 



Fig. I. Graphs representing total ash and individual ash constituents found in 



spinach tops from plots receiving the substances indicated 20 



2 . Graphs representing total ash and individual ash constituents in spinach 



roots from plots receiving the substances indicated 20 



Nitrates, Nitrification, and Bacterial Contents of Five Typical Ac!id 

 Soils Affected by Lime, Fertilizer, Crops, and Moisture 



Fig. I. Graphs showing the relation of aerobes and anaerobes to nitrification of 



five acid soils \\dth and without lime and fertilizer treatments 37 



2. Graphs showing the relation of aerobes and anaerobes to nitrates in five 



acid soils kept at different moisture contents 38 



Influence of Salts on the Nitric-Nitrogen Accumltlation in the Soil 



Fig. I . Graphs showing molecular concentrations at which the highest stimu- 

 lation is noted 128 



2. Graphs showing the percentage of stimulation at the above noted mole- 



cular concentrations (see fig. i), the untreated soil being counted as 

 producing 100 per cent of nitric nitrogen 129 



3. Graphs showing the molecular concentrations at which the various salts 



are toxic to nitrification ■. •. . 130 



4. Graphs showing the molecular concentrations which reduce the nitrifi- 



cation to three-fourths normal 131 



5. Graphs showing the percentages of nitric nitrogen produced in 100 gm. 



of soil to which had been added 2 X lo-^ mole of the various salts, the 

 untreated soil being counted as producing 100 per cent 132 



Physoderma Disease of Corn 



Fig. I. Map showing the distribution of Physoderma zeac-maydis in the United 

 States. Broken lines, P. zeae-maydis present: solid line, P. zeae- 

 maydis causing damage 138 



Injury to Casuarina Trees in Southern Florida by the Mangrove 



Borer 



Fig. I. Chrysoboihris tranqueharica: I,arva, dorsal, lateral, and ventral views.. . 159 

 2. Chrysoboihris tranqucbarica: a, Female pupa, ventral view; b, same, 



dorsal view 160 



