EXPERIMENTS WITH THE DAISY ORGANISM. 51 



Result. — July 13, 1907: The trees were an inch or two in diameter 

 at the base when inoculated and have made a slow growth. No 

 tumors resulted from these inoculations. 



Inoculations of May 26, 1908 (Smith). 



Three vigorous young shoots of Juglans regia pendula were inocu- 

 lated near the growing end with 4-day-old agar streak cultures of 

 the daisy bacterium. 



Result. — July 15, 1908: The 3 shoots developed small tumors in 

 the pricked area within a week or 10 days, and these have continued 

 to grow slowly ever since. Two shoots were put into alcohol July 15. 



DAISY ON WINGED HICKORY. 



Inoculations of May 26, 1908 (Smith). 



Eight young, actively growing shoots of Pterocarya fraxinifolia 

 were inoculated by needle pricks near the growing pomt mth 4-day- 

 old agar streak cultures of the daisy bacterium. The tree stood on the 

 grounds of the Department of Agriculture. 



Result. — July 15, 1908: The Pterocarya proved much more resist- 

 ant than the Persian wahiut. There was nothing on any of the shoots 

 for a month. More recently a few small tumors have developed on 

 3 of the 8 shoots. The others show nothing. Two were put in 

 alcohol. 



DAISY ON GRAY POPLAR. 



Inoculations of April 17, 1907 (Smith). 



Five gray poplar trees (Pojmlus canescens) were inoculated with 

 agar slants 5 days old, each receiving 30 pricks in groups of 5. Four 

 trees were held as checks. There was a natural tumor at the earth's 

 surface on No. 401, wliich was cut off. One also on No. 403 was left 

 to be photographed. The checks received 60 pricks each in groups 

 of 5. The roots of all the trees were washed thoroughly in the lab- 

 oratory before inoculating. The trees were then planted in the 

 greenliouse. 



Result. — July 13, 1907: The trees were in a poor condition when 

 received from the nursery. No tumors resulted from these inocula- 

 tions, probably because the trees made too slow a growth. 



Inoculations of May 25 and 26, 1908 (Smith). 



Some young sprouts (cuttings rooted some weeks previous) were 

 inoculated Alay 25 mth 4-day-old agar streak cultures of the daisy 

 bacterium. 



One shoot on a tree was inoculated May 26 from the same cultures 

 used on May 25. 



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