236 DUPLICATION OF GENERATIVE NUCLEI BY MEANS OF 
Ô. Yellow Hammer abn. W. autogamously and geitonogamously pol- 
linated. The 10 bulbs of Yellow Hammer abn. W. produced 18 in- 
florescences, of which 15 were pollinated autogamously, 2 geito- 
nogamously on thé 11th and 12th of April. On the 12th of May 
the ovaries of 11 inflorescences were not, those of 5 were somewhat 
enlarged, while the 17th inflorescence had formed a considerably 
swollen fruit, which later produced 1, apparently good, seed. The 
18th inflorescence, formed on the plant in the hot, humid glass- 
house, ripened very slowly one fruit, which contained a single - 
seed. This seed however was very large, much larger than any 
I have ever seen on a diploid hyacinth-variety. 
We have seen that one bulb frequently forms more than one inflo- 
rescence. It is therefore a low estimate, when we suppose that each 
bulb has produced on the average 50 flowers, which could be pollina- 
ted, so that at least 2800 flowers have been pollinated. The pollination 
with the abnormally treated Yellow H ammer-plants was no easy task. 
The stamens of these were, at the beginning of the anthesis, soft and, 
as has been said, somewhat ribbon-shaped and soon shrivelled and be- 
came hard. The pollen was then usually removed from them by means 
of preparation-needles while the anthers were on a glass slide, which 
was subsequently gently rubbed over the stigma of the flower to be 
pollinated. | 
It is perhaps not superfluous to state that all plants of Gertrude 
(with single red flowers) and all of Yellow Hammer (with single yellow 
flowers) are derived from one seed, and consequently are clones of a 
single individual. The terms autogamous and geitonogamous polli- 
nation were consequently legitimately used. 
V. EXAMINATION OF THE MIKROTOME-SECTIONS MADE OF THE 
ANTHERS WITH ABNORMAL POLLENGRAINS 
It will be understood, that for this purpose, preferably anthers of 
Yellow Hammer were used. Accordingly, some flowers of the plant of 
the humid, hot glasshouse were fixed in alcohol-acetic acid. On the 
3d of February 1921 after embedding in paraffine, they were cut into 
sections, 15-20 u. thick. These sections were stained with Heidenhain 
iron-haematoxyline, all of which manupulations were kindly executed 
by my wife. 
