PLATE XIX 



153 





154 



153. A view of the front or outlet side of the apparatus used to determine 

 the influence of plants upon the oxidation activities in the soil. Twelve barium 

 hydroxide towers were used for recovering carbon dioxide from air removed while 

 soda lime in the long horizontal tube, lying on the table, freed the indrawn air 

 from carbon dioxide. The six central jars contain barley and soybean plants 

 (from Neller). 



154. Influence of inoculation upon the growth of soy beans in sterilized water. 

 A, Uninoculated; B, inoculated (from Garman and Didlake). 



