198 MR. J. SCOTT ON THE STERILITY AND HYBRIDIZATION 
1. First for P. racemosa as female.—I placed pollen of the 
P. alata No.1 upon the stigmas of ten flowers of the P. racemosa; 
seven of these set, but four of them only reached maturity, and 
yielded an average of 123 apparently good seeds per fruit, while 
the others dropped off early and contained no good seeds. Four 
flowers on the P. racemosa fertilized with pollen of the P. alata 
No. 2 resulted differently, as the ovary of not even one swelled. 
Again, six flowers on the P. racemosa fertilized with pollen of the 
P. alata No. 3 produced three fruits, two of which shanked off 
while the other ultimately maturing yielded 114 apparently good 
seeds. 
By applying pollen of P. cerulea No. 1 to the stigmas of six 
flowers of the P. racemosa, I obtained two fruits; these contained 
235 seeds, of which 197 were apparently good. Pollen of P. 
cerulea No. 2 applied to the stigmas of eight flowers of the 
P. racemosa failed to effect the swelling of even one germen. I 
had ultimately similar results by placing pollen of the P. cerulea 
No. 3 upon the stigmas of eight flowers of the P. racemosa, 
though I had hopes of a different result from the early swelling 
of three germens, but these shanked off. By applying pollen of 
P. edulis to the stigmas of six flowers of P. racemosa, one ovary 
alone swelled, but this dropped off prematurely and contained 
no good seeds. Again, experiments on P. racemosa with pollen 
of the Tacsonia pinnatistipula resulted in the abortion of all the 
ovaries: but I was more successful in my experiments with P. 
racemosa and T. mollissima, inasmuch as from six flowers of the 
former fertilized by pollen of the latter I got three ovaries to 
swell; one of these alone matured, and yielded 142 seeds, of 
which 22 seemed good. Lastly, I fertilized 20 flowers on the 
P. racemosa with own pollen: though, as we have above shown, it 
Keith Hall, Perthshire, for sending me pollen from plants of the P. alata and 
P. caerulea, and likewise for trying experiments on the former species with 
pollen from another individual which I sent him. The results of these experi- 
ments will be given in the sequel. For the sake of brevity, however, I will 
here affix numbers to each of the plants of the P. alata and c@rulea experi- 
mented upon, so that I may not have further occasion for noticing the particular 
plant of which I may be treating; thus, P. carulea, Nos. 1 & 2, refer to plants 
growing in the Botanic Gardens of Edinburgh; P. carulea, No. 3, to a plant 
growing in the gardens, Keith Hall; P. alata, No. 1, plant growing in the 
Botanic Gardens, Edinburgh; P. alata, No. 2, plant growing in the gardens, 
Keith Hall; P. alata, No. 3, plant growing in the nurseries of the Messrs. 
Lawson and Sons, Edinburgh. 
