Summary

Describes how adhesive bladders enable the achenia of Pumilio argyrolepsis to attach themselves to the soil. James Drummond sent seeds to CD with a memorandum on the achenia.

Summary

Discusses the possible explanation of why fly-orchid plants in a correspondent’s garden had no pollen-masses removed while Orchis maculata had all of its pollen-masses removed. CD points out that different orchids are fertilised by different insects. The insects needed to fertilise the fly-orchid may not have inhabited the site of the correspondent’s garden.

Summary

Reports his experiment with fertilising the large periwinkle (Vinca major), which he had never known to produce seed. He found that the pollen could not reach the stigma without the aid of insects, which in England never visit the flower. CD produced seeds by inserting a fine bristle, like the proboscis of a moth. Asks readers to repeat this experiment with other species that do not habitually seed and to report the result.

Summary

Requests orchid specimens from Arethuseae division for his investigation of the many contrivances by which orchids are fertilised by insect agency.

Asks whether Charles Morren has published on the fertilisation of orchids by insect agency.

Summary

Two correspondents report fertilising Vinca rosea by imitating the action of an insect inserting its proboscis. Another says his Vinca rosea seed profusely without artificial fertilisation. CD asks what might explain the difference in results. In the latter instance, are the plants kept in a greenhouse with windows left open, so that moths could get access at night?