CHESTNUT BARK DISEASE. 403 



seedling chestnuts which had been transplanted when one year 

 old, and found 46 per cent, infected with the blight, which had 

 been present there at least two years, and probably started at 

 the time of transplanting. The roots of these plants, when 

 examined, were in good condition. We had the superintendent 

 cut off all the diseased trees in one row (sixty-nine), and in 

 February, 1913, the sprouts that had come from these showed 

 only one that was plainly infected with blight, although they 

 were exposed to the blight from infected seedlings that had not 

 been removed. The first-year sprouts from old stumps also 

 rarely show infection. According to our infection experiments, 

 it usually takes only a month for the canker to show after 

 inoculation, so these one-year-old sprouts had time to show the 

 disease if they were infected. We believe the old, well-estab- 

 lished roots produced unusually vigorous sprouts, which for 

 the time being, at least, escaped infection. 



Vitality versus Chemical Activity. We believe that favorable 

 or unfavorable climatic conditions for a plant are recorded 

 through chemical activities concerned with its growth and 

 vigor, and that a lessening of this chemical activity might with 

 some plants be shown by lessened resistance to fungous attack. 

 The following few references show the relationship of environ- 

 ment on chemical activities of certain plants. 



Hasselbring (Bot. Gaz. 53, p. 120) says: "It is true, of 

 course, that plants are modified in their fluctuating characteristics 

 by changes in the environment, but so far as experimental 

 evidence shows, such modifications persist only as long as the 

 environment inducing them persists. LeClerc and Leavitt, in 

 their work with wheat, showed that this influence of the environ- 

 ment is exerted also on the chemical composition of plants. 

 When wheat of one variety from one locality was grown in other 

 localities with a widely different environment, the chemical 

 composition of the grain was different in each locality. These 

 differences persisted as long as the wheat was grown in the 

 particular locality, but if at any time seed from one locality 

 was grown in any of the others, the grain took on the composi- 

 tion of the wheat constantly grown in those localities. 



Vasey (U. S. Dept. Agr. Rept. 1872, p. 171) mentions a case 

 where the alkaloids of cinchona bark were decreased by unfavor- 

 able climatic conditions in the case of plants grown in England 



