120 MR. J. SCOTT ON THE FUNCTIONS AND STRUCTURE OF THE 
this species (P. mollis) frequented by insects, I carefully pro- 
tected a few plants, in case this regularly complete fertility might 
be due in part to such agencies. The seed-produce, however, 
from these plants was in no way affected; the average of cap- 
sules, and of seed per capsule, was quite equal to those from the 
unprotected plants. The following are the results from a single 
scape of a proteeted plant, which I believe affords a fair idea of 
the average fertility of this species in a cultivated state :— 
Sebel s.m. | oe 
£5 oc m n as, 0 Bry 2 Mn O n n 
PE AEI 23212338 Bg | 35% 
SEE 85 Sga dha) 23] 838 
Be | fq SS Baal an EE 
A A aria "15 1 x 
Primula mollis ......... 4 17 17 14 2306 165 
3. We have thus seen, then, that the Primulas Scotica and 
mollis, in function as in structure, are alike non-dimorphie. This, 
however, does not appear to be the case with the following 
species, P. verticillata, which apparently presents an imperfect 
functional dimorphism in conjunction with a non-dimorphie struc- 
ture! As I have already stated, the anthers in this species are 
attached to the upper third of the corolla-tube, and in general 
closely surround the stigma; occasionally, however, the latter 
rises above the anthers, and even becomes slightly exserted beyond 
the corolla-tube. In such relations, then, of anthers and stigma 
as occur in the latter case, it is at once evident that sterility 
may be simply due to the pollen not reaching the stigma. Any- 
how, the existence of plants producing flowers of the latter 
description renders all but valueless the few observations I had 
made on the self-sterility of this species under cultivation, pre- 
vious to the publication of Mr. Darwin’s paper on Primula- 
dimorphism, inasmuch as I was then utterly ignorant of such 
singular sexual relations, and therefore paid no regard to the 
relative lengths of the stamens and pistils of those plants which 
came under my observation. In respect to these I will therefore 
simply state that for two successive seasons I failed to get a 
single seed from a fine healthy plant of this species, though each 
season it produced a profusion of flowers. I have also received a 
nearly similar testimony from the observations of others, namely, 
that they rarely ever succeeded in getting seed from solitary 
plants of this species, though they have frequently gathered it 
when a few plants were growing together. But for the existence, 
