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Aug. 41

It is well known that characters which is generally same in large groups varies in some.— As form of pollen in Convolvulus, & Forbes mentions other cases.

Again character which generally are good as specific (thus even colour though this is the exception) serve — to distinguish varieties or individuals in others. Thus. Stephens (a) back of page.

This is remarkable analogy— I do not know whether the character which ceases to be generic in any group, ceases generally also to be specific — thus whether form of pollen-grains varies in the individual species of Convolvulus. (—or the converse whether the mandibles of Lucanus B. serve as generic (probably not) if so then in this my doubt is answered)

When a character varies in the species of a genus, but holds good in each species we can

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(a) Thus bracteæ in Orchis maculata & form of petals varies &c &c

Stephens Illustrate v. 3 Append — secondary male characters of Lucanus, though an important an organ, as mandible, varies excessively — as does form of hind-legs in Necrodes littoralis — but Stephens seems to think this connected with fertility or power in male.

B

A character wh varies in the species, whether one or all cannot be good generic character, but a bad generic character, (such as diversity in shape of pollen)

May be good in each species, as it may be fixed.—

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see the parent species must have varied in this character to have given rise to the species — This leads one to speculate on origin of genera; as being true relations.— These facts are also most important, as showing certain causes, tend to make not whole from sport, but certain parts: — Is this owing to action on certain parts as Iodine — or rather to certain peculiarities not being fixed.