OF PASSIFLORA, DISEMMA, AND TACSONIA. 201 
were not materially different, as from six flowers thus treated 
one ovary alone set, but this did not continue swelling. Fourthly, 
six flowers of P. alata No. 1 proved impregnable to pollen of 
Tacsonia mollissima, while a similar number of flowers on the 
former fertilized with pollen of the Zacsonia pinnatistipula differed 
simply in the early setting of two of their ovaries, as neither con- 
tinued swelling. Lastly, I applied pollen of the Disemma Adian- 
toides to the stigmas of six flowers of the P. alata No. 1, but this 
also proved ineffective, as the ovaries of not even one set. 
With respect to the power of self-fertilization in the above 
three plants of P. alata, 1 may state that there is absolute im- 
potence. I have already adduced evidence of this in P. alata 
No. 1 from experiments in the flowering seasons of 1861 and 
1862. I repeated these in 1863 with similar results, as, from 
90 flowers fertilized with own pollen, not one ovary exhibited the 
slightest symptoms of pollinie influence. On the plant of P. alata 
No. 2 a vast number of flowers have been from time to time 
fertilized, but the results showed a most inveterate self-sterility 
in the invariable abortion of every ovary. Again, experiments on 
the susceptibility of P. alata No. 3 to fertilization by its own 
pollen resulted also, according to Mr. Sterling, in the continued 
abortion of the ovaries. I have already stated, in previously 
giving the experiments on the reciprocal fertilization of P. alata 
Nos. 1 & 2, that the pollen of either, on being applied to the 
other’s stigmas, produces pollen-tubes which freely penetrate 
their stigmatic tissues. In the action, however, of either stigma 
on its own pollen there is this material difference, that though it 
occasionally excites the development of the pollen-tubes, it is 
rarely penetrated by them. 
Though the pollen of each of these plants of P. alata is thus 
utterly impotent on its own stigma, we have nevertheless shown 
it to be perfectly good in its relations with other individuals of 
the same species or with distinct species. As further illustrative, 
however, of the potency of the pollen of one of the above plants, 
I will here give the results of experiments with it on the stigmas 
of the Disemma Adiantoides and coccinea, both of which are also 
easily fertilized with their own pollen. Thus, on D. Adiantoides 
I fertilized three flowers by own pollen; each of these set, and 
produced fine plump ovaries, which yielded conjointly 720 good 
seeds. By applying pollen of P. alata No. 1 to six flowers of 
D. Adiantoides, I got four ovaries to set; two of these came to 
perfection and conjointly yielded 258 seeds, of which 46, judging 
