42 Oil Hyhridisatlon of some Species o/Salix 



respect is sharp, and there is never found any transitional form between 

 the two. 



In ^1 I have obtained two sorts of individuals : one of them has its 

 catkins densely covered with long gray hairs as in the one parent 

 S. gracilistyla (below designated as plants of 6^-type from the word 

 gracilistyla) (Plate I, fig. 3, ^ — $ ), whereas the other has its catkins 

 resembling those of 8. multinervis, i.e. sparingly hairy (designated below 

 as plants of iW-type from the word " multinervis") (Plate I, fig. 4, 

 ^ — J). The distinction between the two types of catkins is generally 

 as sharp as between those of the two original parents, though in respect 

 to the male catkins the distinction between the two types is sometimes 

 difficult to be made out. 



Let us first describe the results obtained in the F^ and i^a genera- 

 tions. As above stated (p. 36) I had only 14 i^j individuals, which may 

 be classed as follows : 



1. <9-type 2. M-type 



11 3 



4<r 7? 0<f 3? 



Not one single male plant of i/-type was obtained in i^i, but a few 

 plants belonging to this category appeared in F^. as stated below. 



The following crosses among the F^ plants were made in 1912 and 

 1913, viz.: 



1. 6^-type % X G^-type c/". 



2. i/-type $ X G-type c/". 



The fertilisation if-type $ x if-type (/ was not possible then, because, 

 as just stated, no male plant of if- type appeared in F^. In 1914, 

 however, I got one male F2 plant of this type resulting from the hybrid 

 i¥-type J X (r-type (^ above mentioned (Plate I, fig. 4 </), and I have 

 done the fertilisation between this male and the female ilf-type Fi 

 plant used in 1912 and 1913, thus : 



3. il/-type F,^x if- type F^J', 

 The results of these three fertilisations are as follows : 

 1. G-type 9 X G-type $. 



G-type M-type Total 



78 c? 109 ? 2 c? 30 ? 



Totals 187 32 219 



( = 85 -4°/,) ( = 14-6 7o) 



