82 



interesting experimentSj whicli I shall refer to later. Now I look upon 

 this incident as being one of the most helpful lessons I ever received 

 in immunization, although it delayed my progress to a considerable 

 extent. 



Last year I reported my notes on four sjiecific trees, Nos. 100, 103, 

 106, and 112. I thiiik I can ])robably give you nothing more inter- 

 esting tlian to report additional notes on those same four plants, with 

 one extra — a perfectly healthy tree. Otherwise it may be as a friend 

 said recently while looking over the sitiration, "There are so many of 

 them they cease to be interesting." 



No. 100 — Last report Sept. 28, 1926. Old stock died promptly 

 after cutting off top and grafting, and four new sprouts had developed. 



May 10, 1927. Grafted two of the sprouts with Burbank chestnut. 

 Sept. 2, 1927. One of tlie four sprouts blighted at ti]i and then 

 stopped. New sprout grew out at this point which looks healthy. Other 

 "prout seems healthy. 



One graft healthy. Other graft blighted a little at the top of the 

 stock, opposite the graft. It rather looks as though all these sprouts 

 have some resistance even though the old injected stock died. These 

 plants received no more antigen this year. 



No. 103 — Last re))ort Sept. 8, '26, graft was doing nicely with no 

 further evidence of blight. 



May 4, '27. Injected antigen. (Old and now known to be inac- 

 tive). No evidence of blight and starting out nicely. 



May 30, '27. Still looks O. K. 



June 15, 1927. Blighted at union of bud and stock and extends into 

 old injection scar (which was in the stock and not on the bud). Think 

 perhaps it will come through without new antigen. 



Aug. 31, '27. Went uj) to inject but hardly tliink it worth while. 

 Probably will not recover. 



Sept. 2, '27. Looks at bud as though it were gone (although I did 

 not cut into the bark to make certain of this). It is rather unusual in 

 that no sprouts have yet appeared as this is usually one of the first 

 evidences when the entire circulation has been cut off. 



It will be observed from the above that the two that did not hold 

 up against my manipulations last year have not much more hope this 

 year. No. 100 was not interfered with at all. except grafting two 

 sprouts, but No. 103 had received an inactive antigen which probably 



