E. S. Salmon and H. Wormald 261 



Of the 480 seedlings raised, 189 plants (39 '38 /J proved to be (/ , 

 and 291 (GO-62 7J ?. 



A separate analysis of the records of the two sexes gives us the 

 following figures : 



Analysis o/* 189 (^ seedlirujs of the " wild hop." 



Totals 189 100 



Analysis o/' 291 $ seedlings 0/ the " xvild hop." 



Totals 291 100 



The percentage figures in the two tables given above indicate a 

 higher degree of susceptibility in the $ seedlings than in the </. It 

 would be unsafe, however, to consider this proved, owing to the circum- 

 stance that the observations as to the incidence of the mildew were 

 made at a time peculiarly favourable for attacks on the $ plant. The (/ 

 and the ? plants would need to be tested at a time when each provided 

 the same amount of infectible material before any inference could safely 

 be drawn as to their relative susceptibility. 



Since excellent material to test the susceptibility was always present 

 in the case of the $ plant, it appears safe to use the analysis of the 

 records of the 291 ? seedlings on which to base an estimate of the 



1 Of these, 1 seedling was semi-immune in the greenhouse. 



- Of these, 3 seedlings were immune in the greenhouse. 



•^ Of these, 5 seedlings were immune, and 1 semi-immune, in the greenhouse. 



■• Of these, 5 seedlings were immune in the greenhouse. 



5 Of these, 2 seedlings were semi-immune in the greenhouse. 



