IN SEVERAL SPECIES OF THE GENUS LINUM. 77 
hours, had penetrated the stigmatic tissue, but to what depth I 
did not ascertain. In this case the inaction of the pollen-grains on 
their own stigmas must be due either to the tubes not reaching 
the ovules, or reaching them and not efficiently acting on them. 
In the case of Lythrum Salicaria, which I hope at some future 
time to lay before the Society, there are three distinct forms, each 
of which produces two kinds of pollen; but neither pollen, when 
placed on its own stigma, causes fertility, except occasionally and 
in a very moderate degree ; yet the pollen-tubes in each case freely 
penetrate the stigmatie tissue. 
The plants of L. perenne and of L. grandiflorum grew, as stated, 
with their branches interloeked, and with scores of flowers of the 
two forms close together; they were covered by an open net, 
through which the wind, when high, passed; and such minute in- 
sects as Thrips could not, of course, be excluded; yet we have 
seen that the utmost possible amount of accidental fertilization on 
seventeen long-styled plants in the one case, and on eleven plants 
in the other case, was the production, in each, of three poor cap- 
sules ; so that we may infer that, when the proper insects are ex- 
cluded, the wind does hardly anything in the way of carrying 
pollen from plant to plant. I allude to this fact because botanists, 
in speaking of the fertilization of plants or of the production of 
hybrids, often refer to the wind or to insects as if the alternative 
were indifferent. This view, according to my experience, is en- 
tirely erroneous. When the wind is the agent in carrying pollen, 
either from one separated sex to the other, or from hermaphrodite 
to hermaphrodite (which latter ease seems to be almost equally 
important for the ultimate welfare of the species, though occurring 
perhaps only at long intervals of time), we can recognize structure 
as manifestly adapted to the action of the wind as to that of 
insects when they are the carriers. We see adaptation to the 
wind in the incoherence of the pollen, in the inordinate quantity 
produced (as in the Coniferz, Spinage, &c.), in the dangling anthers 
well fitted to shake out the pollen, in the absence or small size of 
the perianth or in the protrusion of the stigmas at the period of 
fertilization, in the flowers being produced before they are hidden 
by the leaves, in the stigmas being downy or plumose (as in the 
Graminex, Docks, and other plants) so as to secure the chance- 
blown grains. In plants which are fertilized by the wind, the 
flowers do not secrete nectar, their pollen is too incoherent to be 
easily collected by insects, they have not bright-coloured corollas 
to serve as guides, and they are not, as far as I have seen, visited 
