390 REV. GEORGE HENSLOW ON THE 
This condition of subsequently closing after flowering may be regarded as a particular. 1 ! 
instance of a more general principle, of which the next (no. 4. vi.) as well as the case no. 7 i 
are special examples. | 
Another remark may be, perhaps, appropriate here, namely, concerning the use of i 
stamens being epipetalous or epiphyllous, as the case may be. When a corolla expands 1 
under sunlight, and is thus prepared to receive the visits of insects, it necessarily will — 
cause the stamens to spread away from the pistil; but on closing again, as if it had — 
never expanded at all, the corolla brings the stamens forward, and the anthers now come 
in contact with the stigma. ` 
4. vi. In some cases flower-buds never open. That flowers can and do fertilize them- — 
selves by not opening at all, is a fact of frequent occurrence. It often occurs in cold — 
and inclement weather, and late in the season, as autumn, and frequently in the winter — 
if it be mild. I examined a large number of unopened and half-opened buds in the Kew ] : 
Gardens in the autumn of 1876, such being merely the last attempts of the plants that — 
bore them to blossom. The pollen was abundant, and escaping from the anther-cells, — 
but not from the buds; and the pollen-tubes were in nearly all cases penetrating the — 
stigmas freely. Thus of a plant of Gnothera biennis, a half-opened flower, about half an — 
inch long, had its anthers clustering round the base of the stigmas, which, in a normally — 
developed flower with a fully expanded corolla, are elevated considerably above them. 3 : 
The anthers had dehisced without the corolla expanding. The stigmas were viscid ` 
throughout their whole length, and the pollen-tubes were freely penetrating. 
Mr. Meehan observes (Gard. Chron. 1875, p. 327) :— 
"A large number of plants have their pistils covered by their own pollen before the flowers open. 
Of these species among Wistaria, Lathyrus, Colutea, Cercis, Genista, Phaseolus, Pisum, Linaria, Ballota, ` 
Leonurus, and some others. This is particularly the case early in the season ; later the pollen-sacs burst — 
more generally about the same time with the opening of the corolla." 
I have italicized one sentence, as it corroborates some of Mr. Darwin's observations on — 
Papaver vagum, Reseda odorata, and also Mr. Bennett's and my own, that a colder 3 
temperature appears to favour or induce self-fertilization in such plants as are more 3 
inclined to be proterandrous with a relatively warmer temperature. 1 
Mr. Meehan goes on to remark :— : 
“ It may be objected that the covering of the stigma with pollen is not fertilisation, as it requires à 1 
peculiar condition of the pistil to receive it. But pollen has a long vitality. Carriére has found its ` 4 
fertilising power unimpaired after three months old on one species, and other cases have been recorded."  .| 
H. Müller has observed the same fact; for example, he speaks of Chelidonium majus — 
as having the stamens and stigmas mature together, though it be often crossed, but that | 
in wet weather self-fertilization is secured in half-opened buds. 
Besides the, so to say, accidental occurrence of normally conspicuous flowers not open- 
ing in autumn &c., there are many inconspicuous flowers which ripen seed all the year 
round, excepting in very extreme weather and when covered with snow, and do so by 
retaining their buds in an unopened condition. Mr. A. W. Bennett has recorded some 
instances which he observed in the winter of 1860 (' Nature, Jan. 1860); and I can 
corroborate his remarks by instancing several other cases, e. g. Stellaria media. This 
A HRS ^ EC NN iz m SS Si MEET xix á 
Se es a Tee CR UN MERE ee AUS a. R 
