Ikeno . — On Hybridization of some Species of Salix. II. 185 
In my former paper I stated the fact that female inflorescences of 
multinervis covered with paper-bags were never able to bear fruits. 1 
This is quite true, but then only a few branches were used for the ex- 
periment. In view of the results obtained by Mr. Nohara, which are 
described above, the experiments were repeated in 1920 and 1921 on a 
much larger scale than formerly. In 1920 nine trees were chosen for the 
experiment : of these, three (Nos. 1-3 in Table VIII below) which are high 
and copiously branched are derived from the fertilization inter se of male 
and female trees used in my experiments done in 1910 and 1911 ; the 
remaining six are smaller, of which four (Nos. 4-7 in Table VIII) are the 
cuttings from a female tree used in the same experiments, and two are from 
Nos. 26 and 29 in Table I (i. e. plants produced without the action of 
multinervis pollen), designated in Table VIII as Nos. 8 and 9. The 
number of catkins in each tree was as follows : 
Table VIII. 
No. of Trees. 
2 
3 
4 
5 
6 
7 
8 
9 
A T o. of Catkins. 
1,105 
326 
818 
20 
29 
19 
36 
. 55 
95 
Total 2,503 
If we suppose that each catkin bears 100 flowers on average, and each 
flower contains three ovules, both of which are by no means high estimations, 
we should have a total of 750,900 ovules. All catkins enumerated in the 
above table were covered with paper-bags, and left in this condition for 
nearly two months. Though in certain catkins a few ovaries grew up 
somewhat more intensely than others, and consequently attracted our 
attention by their remarkable size, yet all of them, on opening, were found 
either to be quite empty or to contain a few seed-hairs only. All other 
catkins simply dried up and fell, with the exception of two catkins 
from No. 8 in the above table. Thus only from the latter did I get 
four seeds in all. Of these, two, being placed upon a moist filter-paper 
within a Petri dish, came to germination, whilst the remaining two did not. 
Similar experiments were repeated in 19 21 on the same nine trees used 
in 1920. The number of catkins produced in 1921 was somewhat smaller 
than in 1920 ; besides, either a certain number of branches covered with 
bags were broken down, or the latter were torn off by storms which 
1 i. c., p. 54. 
P 2 
