OF PASSIFLORA, DISEMMA, AND TACSONIA. 203 
6. Lastly, I have to notice the results of experiments on 
plants of the Zucsonia pinnatistipula and mollissima growing in 
the Royal Botanic Gardens of Edinburgh. It had been observed 
that the plant of the T. pinnatistipula, though annually pro- 
ducing a profusion of blooms, rarely produced a single fruit; and, 
further, that when the latter were produced the .seeds were 
always imperfect. It thus became the subject of the following 
experiments. In 1862 between 100 and 200 flowers were ferti- 
lized with own pollen, yet from these only three ovaries swelled ; 
one dropped off prematurely ; the two others came to perfection, 
forming large, plump, orange-like fruits. On cutting these open, 
I found in them an abundance of seeds; but these proved all im- 
perfect, as on examination they were found destitute alike of em- 
bryo and surrounding albuminous matter, the hard sculptured 
spermoderms having alone been-developed. From this sterility 
to own pollinie influence, I determined to try these flowers with 
pollen of other species. Accordingly, in 1563, I placed pollen of 
T! mollissima on the stigmas of six flowers of the T. pinnatistipuld; 
of these three set fruits, but two of them shanked off; the one 
which came to perfection contained 190 seeds, of which 52 were 
embryonated. I likewise tried the converse experiment, and placed 
pollen of the T. pinnatistipula on six flowers of the T. mollissima, 
and thus got three ovaries to set; one of these was entirely desti- 
tute of seeds, while the others conjointly yielded 116 seeds, but 
these were all small and imperfectly developed. 
From the results of experiments in 1862, we have seen that 
the Zuesonia pinnatistipula could not be impregnated with its own 
pollen. Nevertheless, from the above favourable results with 
pollen of the Z. mollissima, I determined to again test its impo- 
tence with its own pollen, which is known to be good when applied 
to another species. I accordingly fertilized ten flowers with own 
pollen; but the results simply confirmed those derived from pre- 
vious experiments, as the ovaries of not even one swelled. With 
respect to the self-fertility of the T. mollissima the case is very 
different, as I have found it fruit freely when treated with own 
pollen, and, further, that these fruits yield an abundance of good 
embryonated seeds. 
There is another point here worthy of a passing notice. In 
the above experiments on Passiflora racemosa as female, we have 
seen that this species is susceptible of fertilization by the pollen 
of Tacsonia mollissima. In the converse experiment, however, 
the results are different, the pollen of P. racemosa proving utterly 
