Smithsonian Report, 1935. Hurd-Karrtr 



PLATE 3 



1. Prevention of selenium injury to wheat plants by elemental sulphur treatments of selenized soil. 

 (a) Plants in Pierre clay injured by the addition of 10 p. p. m. selenium as sodium selenate; (6) uninjured 

 where excess sulphur was added also; (c) injured by 20 p. p. m. selenium; (d) uninjured where excess 

 sulphur was added also. 



2. Wheat plants growing in quartz sand containing 0.033 gram of sodium selenate per 7.000 grams of sand 

 and ditTering amounts of sulphate sulphur (as magnesium and ammonium sulphates). The plants are 

 dead with no sulphate (o), almost dead with sulphate supplying 10 p. p.m. sulphur (6), chlorotic with 

 32 p.p.m.Cf), and normal with 96 and 192 p.p. m. (d and e). 



