16 A. L. PlERSTORFF 



0.2 cubic centimeter of toluol; lot 8 was heated to 48° C. for ten min- 

 utes; lot 9, to 49° C. for ten minutes; lot 10, to 48° C. for fifteen 

 minutes; lot 11, to boiling for ten minutes; lot 12 was left untreated. 



After the various lots had been treated as indicated, cultures were 

 plated from two tubes of each lot to ascertain whether or not the fire- 

 blight bacteria had been killed. It was found that juice from blighted 

 fruit treated with 5 per cent of chloroform and that treated with 1 per 

 cent of toluol did not always give sterile cultures unless it was well 

 shaken after addition of the germicide. This precaution was observed 

 in subsequent tests. One tube from lot 8 was found to contain live 

 bacteria, and in later tests all heated tubes were heated either to 48° C. 

 for fifteen minutes, or to 49° C. for ten minutes. 



The freshly cut ends of rapidly growing French seedling crab-apple 

 shoots were inserted in two tubes of each lot, and the results were noted. 

 Thirty minutes after the twigs were inserted, the tips of those in the 

 tubes containing heated juice from the blighted fruit began to droop. 

 In a few minutes, the twigs in the other tubes containing juice from 

 blighted fruit lost some of their turgidity. After forty-five minutes. 

 ;ill the twigs in the juice from blighted fruit, irrespective of subsequent 

 treatment of the juice, showed some wilting. The twigs in the heated 

 juice w r ere drooped as far as the morphological structure of the stem 

 permitted. The checks were all turgid except in those tubes containing 

 phenol, 10 per cent of chloroform, and 20 per cent of chloroform. 

 Equivalent amounts of these germicides in distilled water caused similar 

 drooping after forty-five minutes. Heating the juice from healthy green 

 pears or adding 1 per cent of toluol appeared to have little influence on 

 the apple shoots during a period of two and one-half hours. At the 

 end of this time all the twigs in tubes containing juice from blighted 

 fruit were drooped, while the checks were turgid except in those cases 

 previously noted. The tests w T ere repeated three times with different 

 lots of pears, and comparable results were obtained in each case. 



After two hours, some of the waited twigs were removed from the 

 tubes of juice from blighted fruit, about an inch of stem was cut off 

 the base under water, and the twigs were placed in water to note whether 

 recovery occurred. At the end of two hours the twigs were again 

 turgid. Shoots that had been in the juice from blighted fruit for 

 twenty-two hours did not regain turgidity when they were removed to 

 distilled water. 



At the end of fourteen hours, one set of twigs was removed, the 

 solutions were diluted 50 per cent with distilled water, and fresh twigs 

 were inserted. Again the same drooping action was noted, but the time 

 interval was approximately doubled. 



It was at once apparent that mechanical clogging might account 



