148 $ DIMORPHISM IN THE GENITALIA OF FLOWERS. 
very prolific of seed. Here the stigma is, and must needs, be, ferti- 
lized by pollen from the anthers of the same flower, the two being shut 
up together in the same closed bud... The acaulescent Violets and the 
common wild species of Impatiens are good examples of the kind. ;; In 
fact, here impregnation is effected as it were in the early bud 5, where- 
fore we had indicated these as cases of precocious fertilization. , Here 
the pollen is unusually active, sending out. its tubes while. still in the 
anther, and thereby, in Impatiens, etc., attaching the anthers. to, the 
stigma. In the first case, Nature takes great pains to secure the cross- 
fertilization of individuals of the species; in the other, on. the, con- 
trary, she takes equal pains to secure self-fertilization, . The end in the 
first case, as Mr. Darwin maintains (we believe upon good philoso- 
phical grounds, now in the course of vindication by experiment), is to 
ensure the perpetuation of the species, since close-breeding or continued 
self-fertilization tends to sterility, while wider breeding is reeuperative. 
We leave it to Mr. Darwin’s sagacity to ascertain the end in the oppo- 
site case, noting that here the most undoubted close-fertilization for in- 
finite generations shows no apparent tendency towards sterility, but 
rather the contrary. 
From another point of view which we are accustomed to take, how- 
ever, we may suppose that as one result of the cross-fertilization must 
needs be to keep down variation by repeated blendings, so the design 
of close-fertilization may be to allow and to favour the perpetuation of 
varieties ; self-fertilization, without selection, being just the condition 
which should most favour both the multiplication of new varieties and 
their preservation. "That such would be the operation, as long ago 
expounded,* appears to us so clear, that we were somewhat surprised 
at finding that tbe reviewer of Darwin's Primula paper in the ‘ Natural 
History Review’ (ii. p. 238) regards the separation of sexes, and there- 
fore cross-fertilization, as favouring variation, and self-fertilization as 
necessarily inimical to it. This probably comes from not considering 
that while close-breeding tends to keep a given form true,—in virtug 
of the ordinary likeness of offspring to parent,—it equally and in the 
same way tends to perpetuate a variation once originated from that form, 
and also, along with selection (natural or artificial), to educe and fur- 
ther develope or confirm said variety. On the other hand, free — 
breeding of incipient varieties inter se and with their original types 18 
* ‘American Journal of Science and Art, vols, xvii and xix... 4 
