68 
Cutting . — On the Pollination Mechanism of 
withered. The first few flowers to be pollinated by hand were not covered 
afterwards, but the last few were more carefully treated. They were 
unopened, but adult, flowers, and they were bagged after the pollination had 
been effected. Self-pollination and cross-pollination both gave rise to 
young fruits : these did not mature ; this was not due to any deficiency 
on their part, but to a withering away of the inflorescence axis. I hope, in 
time, to overcome what is probably only a cultural difficulty and to get the 
seeds to ripen and to germinate. 
Pollen of Incarvillea . 
The pollen-grains (Fig. 3) resembled those of Thunbergia alata as 
figured by Goebel (6) in the e Outlines of Classification and Special Mor- 
Fig. 3. Pollen-grains of Incarvillea Delavayi, a-f, and of 1 . grandiflora , g-l. All x 330. 
a and B, same grains at upper and lower focus respectively, B with the slits seen in A dotted in. 
C and D, upper and lower views of the same grain. E, an air-dried grain, f, size of grain in 25 % 
sugar solution. G and H, same grain at upper and lower focus. K, a similar grain. L, a small 
grain, (a, B, C, D after treatment with sulphuric acid.) 
phologyj. They were dry, and on placing them in water they were imme- 
diately ruptured ; even in a mixture of equal portions of water and glycerine 
the majority of the grains were destroyed after a few minutes. The exine 
was cutinized and was resistant to the action of sulphuric acid ; while the 
intine was dissolved in this reagent and gave the usual tests for cellulose. 
After such treatment, and occasionally before treatment, when mounted in 
strong sugar solutions, it could be seen that the outer wall was covered with 
