[86]

Dichogamy

Isotoma (a Lobeliad) white flow. Nov. 12. 1862. has curious long pointed filament from summit of united anthers, projecting rectangularly into gangway to nectary; when struck as must be by insect, pollen is shaken on to insect. After most pollen spilt, stigma protrudes & open, as in Lobelia. —

5 plants in pots in Greenhouse, were not watched, but were not seen to be visited by bees & produced 12 24 good pods & 13 very poor pods (= 37 pods altogether) ─12 good pods yielded 6.1 gr. of seed. 24 [+] 13 [=] 37

5 plants protected from insects in Greenhouse, & seemed equally healthy, produced only 16 good pods & 20 36 very poor ones (= 36 altogether)

12 of the good pods yielded only 3.5 gr of seed. — Hence it would appear that

[86v]

[calculations not transcribed]

[87]

covering checked in every way production of seed; we may say uncovered produced in 24 pods 12.2 gr & 16 covered pods produced only 4.66 gr. — But we learn fact, that Isotoma is considerably self-fertile — I presume pollen not well scraped out on anther.