[117]

Sea Kale

F 125

1/4 scale 7 sets of lettering

see back for description

[117v]

65 676

Chap. E 10

young flowers are exclusively male in function, and the older ones exclusively female; and as bees habitually alight low down on the spikes of flowers in order to crawl easily upwards, they get dusted with pollen from the uppermost flowers, which they carry to the stigmas of the lower and older flowers on the next spike which they visit. The degree to which distinct plants will thus be intercrossed depends on the number of spikes in full flower at the same time on the same plant. With proterogynous flowers and with depending racemes, the manner in which insects visit the flowers ought to be reversed in order that distinct plants should be intercrossed.

But this whole subject requires further investigation, as the great importance of crosses between distinct individuals, instead of merely between distinct flowers, has hitherto been hardly known recognised.

In some few cases the special movements of certain organs almost ensure pollen being carried