nnatifid;
(4) in the extremity being acute or blunt; (5) in the base being sharp,
blunt, or cordate; (6) in the surface being pubescent or smooth; (7) the
perianth varies in depth and lobing; (8) the stamens vary in number,
independently; (9) the anthers are mucronate or blunt; (10) the fruit
stalks vary greatly in length, often as one to three; (11) the number of
fruits varies; (12) the form of the base of the cup varies; (13) the
scales of the cup vary in form; (14) the proportions of the acorns vary;
(15) the times of the acorns ripening and falling vary.

Besides this, many species exhibit well-marked varieties which have been
described and named, and these are most numerous in the best-known
species. Our British oak (Quercus robur) has twenty-eight varieties;
Quercus Lusitanica has eleven; Quercus calliprinos has ten; and Quercus
coccifera eight.

A most remarkable case of variation in the parts of a common flower has
been given by Dr. Hermann Mueller. He examined two hundred flowers of
Myosurus minimus, among which he found _thirty-five_ different
proportions of the sepals, petals, and anthers, the first varying from
four to seven, the second from two to five, and the third from two to
ten. Five sepals occurred in one hundred and eighty-nine out of the two
hundred, but of these one hundred and five had three petals, forty-six
had four petals, and twenty-six had five petals; but in each of these
sets the anthers varied in number from three to eight, or from two to
nine. We have here an example of the same amount of "independent
variability" that, as we have seen, occurs in the various dimensions of
birds and mammals; and it may be taken as an illustration of the kind
and degree of variability that may be expected to occur among small and
little specialised flowers.[29]

In the common wind-flower (Anemone nemorosa) an almost equal amount of
variation occurs; and I have myself gathered in one locality flowers
varying from 7/8 inch to 1-3/4 inch in diameter; the bracts varying from
1-1/2 inch to 4 inches across; and the petaloid sepals either broad or
narrow, and varying in number from five to ten. Though generally pure
white on their upper surface, some specimens are a full pink, while
others have a decided bluish tinge.

Mr. Darwin states that he carefully examined a large number of plants of
Geranium phaeum and G. pyrenaicum (not perhaps truly British but
frequently found wild), which had escaped from cultivati