Describes difficulty of obtaining pigs for experiment.

Has signed William Darwin’s certificate of nomination to Geological Society.

Gives details of his Fisheries appointment.

Thanks AdeC for interesting letter. CD has been annoyed by the multitude of new terms lately invented in all branches of biology in Germany. What AdeC says about the word "purpose" made CD vow not to use it again, but it is difficult to cure oneself of a vicious habit and difficult to avoid for anyone who tries to make out the use of a structure.

Francis will write about the diagram [see 13642].