Describes his experiments in fertilising Oncidium flexuosum and comparison with Notylia.

Has been examining Catasetum.

Encloses seeds of two species of Gesneria and describes hairs in the seed capsule. Hairs in other plants seem to have a different function.

Starting tomorrow for a botanical excursion on the Continent.

Thanks for CD’s letter inquiring about capsules produced by the Maxillaria with larger pods [see 5331]. Gives descriptions of Maxillaria and of the other Vandeae.

Describes Oncidium flexuosum.

Tells of botanical results of recent excursion to the German colony Theresopolis. Brought home fine collection of living orchids.

Reports observations on fertility of orchids he has self-pollinated and crossed with pollen of other species.

Cites cases of difference in coloration between the sexes of some species of Crustacea, annelids, and spiders.

Discusses dimorphic plants and self-sterility.

Outlines some experiments involving the crossing of different species of orchids.

Encloses extract from Carl Claus, Die freilebenden Copepoden [1863].

Discusses dimorphism in plants, especially the Rubiaceae.

Gives observations on orchids; notes varying degrees of self-sterility and a varying success at crossing distinct species.

Mentions local ferns he is collecting

and considers the phenomenon of apparently mimetic plants.

Thanks CD for sending F. H. G. Hildebrand’s book on fertilisation [Die Geschlechter-Vertheilung bei den Pflanzen (1867)]

and J. D. Hooker’s "Lecture on insular floras".

Describes work on Rubiaceae, Oxalis,

and on crossing orchids. Lists crosses made.

As for CD’s query concerning sexual differences among invertebrates, he gives the case of the local amphipod, Brachyscellus diversilor. Male differs in shape of antennae and coloration.

Also mentions local fish in sea near Sta Catharina which emits melodic tone to attract females.

Has CD ever considered that the colour of seeds of Amarantaceae would attract the attention of birds?

Describes case of a climbing Chamissoa of the local flora.