Summary

Thanks for CD’s answers on Passiflora

and Asa Gray review.

Has observed gradation of sterility in Oncidium species.

Has observed rostellar germination and fertilisation in Laelia. The latter was prevented in Bletia by covering the stigma with plaster of Paris.

Gongora atropurpurea capsules are swelling.

Summary

Enthusiastic about JS’s work on Passiflora self-incompatibility.

CD quotes JS on rostellar pollen germination [in "Fertilisation of orchids", Collected papers 2: 77–8]. H. Crüger attributes it to ants’ carrying stigmatic secretion to pollen.

Homomorphic cowslip seedlings are, sadly, showing variation.

Summary

Answers JS’s criticism of natural selection, which he doubts JS understands. CD does not believe in an "innate selective principle".

To understand "utility" JS should read CD on correlation.

Origin of maize: no longer thinks husked form was wild because of Asa Gray’s evidence on its variability.

Has information from Thomas Rivers on weeping habit in trees.

JS’s experiments on coloured primroses.

Encloses bibliographical note on Passiflora.

Summary

JS criticises natural selection as based on an innate "continuously watchful selective principle".

Seeks seed of wild Rocky Mountain maize.

What is CD’s view on origin of maize?

Seeks information on self-sterility of Passiflora and Lobelia.

Weeping habit of trees.

Intended to say bisexual plants presented more established varieties than unisexual, not that they are more variable.

Explains his opinion that homomorphically fertilised Primula will produce only their own form. Is trying homomorphic crosses with different coloured Primula varieties.

Asks to read Asa Gray’s 2d review of Orchids.

Has finally successfully fertilised Gongora, but it was done by unnatural means.