E. S. Salmon 147 



Table I. 



List of Seedlings showing Immuyiity to Mildew, in the 

 greenhouse, throughout the season of 1920. 



In bcth cases the cuttings had been potted up in the same kind of soil 

 and grown under the same conditions. The former plants, however, 

 became naturally infected with mildew by conidia disseminated in tbe 

 air of the greenhouse. In those cases where an asterisk is placed in the 

 table given below, the seedhng showed extreme susceptibiUty ; in the 

 other cases the susceptibility shown was normal^. 



Table II. 



List of Seedlings {of the same origin as in Table I) showing 

 Susceptibility to Mildew, in the greenhouse, throughout the season of 1920, 



Ref. no, of No. of clone- 



^ These seedlings had not previously been tested; the remainmg 20 seedlings had shown 

 the same resistance in previous seasons. 



- As further evidence of the severity of the inoculation to which the "immune" 

 seedlings were exposed, and of the presence of suitable conditions for the growth of the 

 mildew, it may be mentioned that 63 cuttings of various commercial varieties of hops 

 stood in the same greenhouse and that all these became naturally infected within three 

 weeks. 



