MISCELLANEA. 
477 
powerless on pollen from stamens of the same form, while the pollen- 
grains of the opposite form emit their tubes freely in a few hours, 
“ the two pollens and the two stigmas mutually recognising each 
“ other.” And with regard to fertility, he says that “ it is no exagge- 
“ ration to say that the pollen of the long-styled Linum grandiflorum 
“ (and conversely of the other form) has been differentiated, with 
“ respect to the stigmas of all the flowers of the same form, to a 
“ degree corresponding with that of distinct species of the same 
“genus, or even of species of distinct genera.” The experiments 
upon which these conclusions are based are described in detail, 
and wholly substantiate what is stated. 
In Linum perenne , besides a short and long pistil, the stamens of 
the long-styled are “hardly more than half the length of those of 
“ the short-styled,” the stigmas of the former “ turn round so as 
“to face the circumference of the flower” about the time that it 
expands. In this species also Mr. Darwin finds abundant evidence 
to prove “ that the stigmas of each form require pollen from the 
“ stamens of corresponding height produced by the opposite form.” 
The object gained by the divergence of the stigmas of the short- 
styled Linum grandiflorum , is sufficiently manifest, since the nectar 
secreted by the flower, and which serves to attract insect visitors, is 
formed at the base and outside of the stamens. This necessitates the 
insertion of the proboscis of the insect between the petals and 
stamens, and insures a supply of foreign pollen upon the upturned 
projecting stigmas. In L. perenne we have stated that the stamens 
are of two lengths, thus “ the pollen will adhere to different parts 
“ of an insect’s body, and will generally be brushed off by the stigmas 
“ of corresponding height, to which stigmas each kind of pollen is 
“ adapted.” Two other important points are referred to, incidentally, 
by Mr. Darwin. “Botanists,” he says, “in speaking of the ferti- 
“ lization 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 entirely 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 
“ case 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 ac- 
“ tion 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 Coniferse, 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 Graminese, 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 inco- 
“ herent to be easily collected by insects, they have not bright- 
