[216]

July 27th

Arachis Hypogæa

[data not transcribed]

[216v]

735 (21

Chapter XI

by humble bees, without a hole in it; and Mr Gentry in speaking of the introduced Wistaria sinensis says "that nearly every flower had been perforated." * (back)

As far as I have seen, it is always humble-bees which first bite the holes, and they are well fitted for the work by their powerful mandibles; but hive bees afterwards profit by the holes thus made., but

Dr. H. Müller however, writes to me that they hive-bees sometimes bite holes through the flowers of Erica tetralix. No insects except bees, and in the with the single exception of wasps in the case of the Tritoma, wasps have sense enough, as far as I have seen observed, to profit by the already made holes which have been made by bees. Even humble-bees do not always discover that it would be profitable advantageous to them to perforate certain flowers: there is an abundant supply of nectar in the nectary of Tropaeolum tricolor, and I have found this plant untouched in more than one garden, while the flowers of other plants had been extensively perforated; but a few years ago Sir J. Lubbock's gardener assured me that he had seen humble-bees boring through

[217]

July 31 Arachis

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(Used)

[217v]

761 (618

Chapter XII

Gen con

with another, the offspring did not profit in the least by the cross. as their progenitors had been kept all the time under the same conditions as nearly as was possible Mimulus offers another case instructive case, showing clearly that the benefit of a cross depends at on the previous treatment of the progenitors: some plants which had been self-fertilised for the last eight previous generations were crossed with plants which had been intercrossed for the same number of generations, all having been kept under the same conditions as far as possible; seedlings from this cross were grown in competition with seedlings others derived from the same self-fertilised mother-plants crossed by a fresh stock; and the latter seedlings were to the former in height as 100 to 52, and in fertility as 100 to 4. An exactly parallel experiment was tried on Dianthus, with this case difference that the plants had been self-fertilised only for the last three generations, and the result was similar though not so strongly marked. The two cases lately advanced of the offspring

[218]

August 2d

Arachis gynophore

August 2d

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Used

[218v]

[fragment]

760 (617

espondence probably depends follows

ing largely governed by chiefly determined by the number of the pollen-tubes

will be determined governed by the

nd the stigmatic secretion or

d constitutional vigour of

ned only by the number of pollen-tubes reaching by this reaction between

raction between

and ovules.)

[illeg]

[illeg] all visibly

that the advantages of cross-

some mysterious virtue in the