[206]

Stolon of Strawberry may 19th to May 21st 1878

Right Hand Fig 2 B

Stolon of Fragaria

same scale 5 sets of Lettering Fig 117

[207]

(Fragaria: circumnutation of some stolon as in the last diagram, figure & observed in the same manner; & traced from 8° am. on May 19th to 8° am. on 21st.

[207v]

593 (37)

Chapter 0 9

and fertility of the seedlings raised from self-fertilised and crossed seeds; for we have already seen that the two classes of cases do not by any means run parallel.

This want of parallelisms would be intelligible if it could be shown that on the one case and not in the other, the self-sterility depended solely on the incapacity of the pollen- tubes from the pollen-grains of the same flower to penetrate the stigma deeply enough to and so as reach the ovules, (a) (text) Now it is certain that with some (173) plants the stigmatic secretion or tissues does not probably properly excite the pollen-grains, if these came as are taken from the same flower. Although in several of the foregoing self-sterile plants the pollen tube were seen to penetrate the stigma yet This is the case according to Fritz Müller with Eschscholtzia, they for he found that the pollen-tubes did not penetrate

the stigma deeply;*(*Bot. Zeitung 1868 p 114 & 115) and with the Orchidaceous genus Notylia they failed altogether to penetrate the stigma. ) it.)

With dimorphic and trimorphic species, an illegitimate union between plants of the same form presents the closest analogy with self-fertilisation, whilst a legitimate union closely resembles cross-fertilisation; and here again the lessened fertility or complete sterility