[264]

Jan 11th—

Vegetable marrow (Radicle)

Diagram B [Figure]

[265, 266 and 267]

Fig. 18

Jan 10th. 78

Vegetable Marrow Diagram A

(natural scale no lettering Magnified 13.6 times

Fig 18 circumnutation of radicle

Fig. 18

Cucurbita ovifera. Fig 18. movement of radicle traced on horizontal glass in darkness from 11°25' a.m to 10° 27' P.m Movement of bead magnified 14 times

Fig. 19.

Vegetable marrow

Jan. 15 & 16th Movement of upper part of plumule

Fig 19 (1/2 scale) no lettering [Figures]

Cucurbita ovifera. Fig 19. movement of hypocotyl at a very early period of growth whilst still arched traced in darkness on a horizontal glass from 8° a.m to 10° 20' a.m on the following day. Movement of bead magnified 20 times & 10 in figure.

[267v]

(8

Much more likely to occur with the short-styled form, for when I inserted a bristle or other such object into the corolla of this form, & had therefore to pass it to between the anthers seated round the mouth of the corolla, some pollen was almost invariably carried down & left on the stigma. Minute insects, such as Thrips, which) sometimes haunt the flowers, would likewise be apt to cause the self-fertilisation of either form; & pollen might easily fall from the anther on the stigma of the short-styled form.

These facts & considerations led me to try the power of the two kinds of pollen on the stigmas of the two forms. Four Four essentially different unions are possible, namely the fertilisation of the stigma of the long-styled form by its own-form pollen, & by that (of the short styled; & the stigma of the short-styled form by its own-form pollen, & by that of the long-styled.

[insertion:] 13 different

The fertilisation of either forms with pollen from the

[Forms of flowers, pp. 23-24: "But this will be much more likely to occur with the short-styled form; for when I inserted a bristle or other such object into the corolla of this form, and had, therefore, to pass it down between the anthers seated round the mouth of the corolla, some pollen was almost invariably carried down and left on the stigma. Minute insects, such as Thrips, which sometimes haunt the flowers, would likewise be apt to cause the self-fertilisation of both forms.
The several foregoing facts led me to try the effects of the two kinds of pollen on the stigmas of the two forms. Four essentially different unions are possible; namely, the fertilisation of the stigma of the long-styled form by its own-form pollen, and by that of the short-styled; and the stigma of the short-styled form by its own-form pollen, and by that of the long-styled."]