[85]

Phalaris Heliotropm obscure light Sept 14

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[85v]

6

Introduction

leads to self-fertilisation: but this end could have been gained far more safely if the flowers had been completely closed, for then the pollen would not have been injured by the rain or devoured by insects as often happens and moreover in this case a very few pollen grains small quantity of pollen would have been sufficient for fertilisation, instead of millions of grains being produced. But the openness of the flower and the production of a great and apparently wasteful production amount of pollen are necessary for cross-fertilisation. These remarks [line excised]

[Cross and self fertilisation, p. 3-4: "The close proximity of the anthers to the stigma in a multitude of species favours, and often leads, to self-fertilisation; but this end could have been gained far more safely if the flowers had been completely closed, for then the pollen would not have been injured by the rain or devoured by insects, as often happens. Moreover, in this case, a very small quantity of pollen would have been sufficient for fertilisation, instead of millions of grains being produced. But the openness of the flower and the production of a great and apparently wasteful amount of pollen are necessary for cross-fertilisation. These remarks are well illustrated by the plants called cleistogene, which bear on the same stock two kinds of flowers.

[85bis]

muslin over from [word obscured] ─ morning bright Sept 16th

Phalaris & Towel additional (used)

[85bis v]

(129, P

(Ch. 3 Houstonia

The Botanic Gardens, when it was not likely that they would have been visited by insects which that had previously visited long-styled plants, produced capsules, eleven of which were wholly sterile, one had contained four seeds, another another eight seeds. So that the short-styled form seems to be very sterile with its own pollen)

( Prof. Asa Gray informs me that the other N. American species of this genus are likewise heterostyled.)

(Oldenlandia sp.?─)

Mr. J. Scott sent me from India dried flowers of a heterostyled species [line obscured]

[Forms of flowers, pp. 132-3: "Selected capsules from some long-styled plants growing in the Botanic Gardens at Cambridge, U.S., near where plants of the other form grew, contained on an average 13 seeds; but these plants must have been subjected to unfavourable conditions, for some long-styled plants in a state of nature yielded an average of 21·5 seeds per capsule. Some short-styled plants, which had been planted by themselves in the Botanic Gardens, where it was not likely that they would have been visited by insects that had previously visited long-styled plants, produced capsules, eleven of which were wholly sterile, but one contained 4, and another 8 seeds. So that the short-styled form seems to be very sterile with its own pollen. Prof. Asa Gray informs me that the other North American species of this genus are likewise heterostyled.

OLDENLANDIA [SP. ?] (RUBIACEÆ).

Mr. J. Scott sent me from India dried flowers of a heterostyled species of this genus, which is closely allied to the last."]