Bui. 169, U. S. Dept. of Agriculture. 



Plate I. 



\. 4 



Ji.S./fctrHe 



Healthy and Acid-Injured Pine Seedlings. 



7 



Fig. 1. — Pinus divaricata, healthy seedling. (X2.) Fig. 2. — P. divaricata, acid 

 injured. (X2.) Probably not capable of recovery. The root growth was 

 stopped before the seedling came up. The entire development of the stem 

 and. leaves above ground has taken place since the cessation of root growth. 

 Fig. 3. — P. laricio, acid injured. (X 2.) Injured when so little root had 

 developed that there was no possibility of a resumption of growth. Illustra- 

 tion made 10 days after the killing concentration occurred. Fig. 4. — P. 

 laricio, acid injured. (XI?.) Recovering by terminal resumption of root 

 growth, as shown by the white root tip. 



