8. Ikkno 35 



grains will remain eflri«ctivo for a very lon^ tiinf, hh Wichura hiu* 

 already indic4it<Ml». 



Branches* with fiMnalo iiirtnrt»Mcencf.M \v<'n* i'IK'Ios<k1 in a |Ni|><r haj( 

 two or thriH* days bi»fore their flowers Ix'^an t<» o|h'Ii. Whrii thin Untk 

 place the inflorescomvs wrre nihhcd with a hair-|H'nril rovm'd with 

 pollen, and thisprow'^s was rejK'at^'d fors<'Vi'nil dayH till all <)|H'nril Howitm 

 had been dusted with it. Tho pajKT Imi^ w^ih rnnovrd when the 

 pnHruding stiginius of all flowt'rs had shrivelled and there wjis n<» more 

 danger of con Uunination by undesired |x»IIen. If hybridisjition HticccedH 

 the stigintis shrivel aft^T two or throe days, and the ovaries Ix-gin to 

 swell gradually; but if not, the stignuus remain jx»rfectly fresh for many 

 days, and the Ciitkins finally fall off. Fruits are generally rifH' in May. 

 Seeds were sown in a pt)t immediately aft<'r their collection, because, as 

 Wichura hjis already shown', they very soon lose their germinating 

 power. Seeds begin to germinate after two or three days, and seedlings 

 grow fairly rapidly. In March of the next year they are transferre<l 

 from the pot to the earth. Many of them come to flower in their thin I 

 year but sometimes much later. 



II. Breeding Experiments. 



Though the hybridisations between several species of Salix cultivated 

 in our Botanical Garden in Komaba near Tokyo were performed with 

 success*, I shall deal here chiefly with that between Salix purpurea 

 var. multinervis (below designated simply as S. multinervis, Japanese 

 name = Inukoriyanagi) and S. gracilistyla (Japanese name = Xeko- 

 yanagi)*. 



These two species grow wqld in the vicinity of Tokyo, and in 1910 

 I found one female plant of «S. multinervis and one male of S. gracilistyla 

 cultivated in our Botanical Garden which had some time previously 

 been transplanted from their respective natural localities. In that 

 year I effected the hybridisation between these two plants, a process 

 which seems to take place with great difficulty, because though I have 

 dusted many female catkins with protruding stigmas repeatedly with an 



* Wichura, /. c. p. 5. 

 « L. c. p. fi. 



' The table placed at the end of this paper will indicate all hybridisations done by me, 

 with their respective successes and failures. 



* As to the scientific names of these two .S'a/ix- species the opinions of our systt-matists 

 do not accord with each other, and I do not know whether or not the nanus employed in 

 this paper are really the correct ones. 



3—2 



