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 abstracted for insertion in his sterility chapter [Variation 2, ch. 18], FM’s observations of plant’s pollen being poisonous to itself.

Occurrence of mimetic plants.

Colouring of Planariae.