PLATE 5 
A. —Air-dried root systems of trees i and 85, in sand and soil, respectively, receiv¬ 
ing Hoagland's nutrient solution. 
B. —Root systems of trees 3 and 86, in sand and soil, respectively, receiving Hoag¬ 
land’s nutrient solution. Note the more finely divided root systems in the soil 
culture. 
