PLATE I. 



1, Nutrient sol.; No. 2, Nutrient sol.+CaCOs; No. 3, Nutrient sol.+CaSOi; 

 No. 4, Nutrient sol.+2 c.c. Al sol.; No. 5, same as No. 4+CaCO.;; No. 6, same 

 as No. 4+CaS04; No. 7, Nutrient sol.+l c.c. Al sol.; No. S, same as No. 

 7+CaCO,i; No. 9, same as No. V+CaSOi. 



PLATE II. 



n ^a 



No. 1, Nutrient sol.; No. 2, Nutrient sol. +CaC03; No. 3, Nutrient sol.+CaS04; No. 

 4, Nutrient sol. +5 c.c. Fe sol.; No. 5, same as No. 4+CaC03; No. 6, same as 

 No. 4+CaS04; No. 7, Nutrient sol.+2 c.c. Fe sol.; No. 8, same as No. 7+CaCo3; 

 No. 9, same as No. 7+CaS04; No. 10, Nutrient sol.+l c.c. Fe sol.; No. 11, 

 same as No. lO+CaCOs; No. 12, same as No. lO+CaSOi. 



