[57]

(1) Cotyledon of Cabbage Red

Oct 7th [Figure]

(Copied by Frank)

Fig 5 7 not reduced (the 2 parts must be joined & first tracing made)

Vertical glass movement of whole plant

exposed to light

[57v]

(50) 606

Chapter D 9

Formerly it appeared to me probable that the increased fertility of these dimorphic plants might be accounted for by the pollen lying so close to the stigma as that it acted was impregnated at the most favourable period age and time of the day; but this explanation is not applicable in to the previously mentioned plant other cases, in which the flowers of which were artificially self fertilised with their own pollen by me.)

(Considering the facts now given, including the appearance of the new varieties which were more fertile and great taller than their parents and than the intercrossed plants of the same corresponding generation, it is difficult to avoid suspecting that self-fertilisation must be in some respects advantageous; though if this be really the case, only any such advantages is as a rule quite insignificant compared with that from a cross with a individual distinct plant & especially with one of a fresh stock. Should this suspicion be hereafter found true, it would throw light, as we shall see in the next chapter, on the existence of plants becoming bearing small and inconspicuous flowers which are rarely visited by insects, and therefore are only (rarely) rarely intercrossed.)

Relative weight and ratios rates period of germination of seeds from crossed and self-fertilised flowers. An equal number of seeds from [text excised]

[Cross and self fertilisation, pp. 351-2: "Formerly it appeared to me probable, that the increased fertility of these dimorphic plants might be accounted for by the stigma lying so close to the anthers that it was impregnated at the most favourable age and time of the day; but this explanation is not applicable to the above given cases, in which the flowers were artificially fertilised with their own pollen.
Considering the facts now adduced, including the appearance of those varieties which are more fertile and taller than their parents and than the intercrossed plants of the corresponding generation, it is difficult to avoid the suspicion that self-fertilisation is in some respects advantageous; though if this be really the case, any such advantage is as a rule quite insignificant compared with that from a cross with a distinct plant, and especially with one of a fresh stock. Should this suspicion be hereafter verified, it would throw light, as we shall see in the next chapter, on the existence of plants bearing small and inconspicuous flowers which are rarely visited by insects, and therefore are rarely intercrossed.
Relative Weight and Period of Germination of Seeds from crossed and self-fertilised Flowers.—An equal number of seeds from flowers fertilised with pollen from another plant, and from flowers fertilised with their own pollen, were weighed, but only in sixteen cases. Their relative weights are given in the following list; that of the seeds from the crossed flowers being taken as 100."]