Summary

Thanks AA for letter on coral reefs. "I used to think … that areas of elevation and of subsidence must – as a general rule be separated by a single great line of fissure, or rather of several".

Suggests that AA urge again his views on reappearance of old characters.

Summary

Is mapping coral distribution on the Tortugas reef. His observations on the Florida peninsula suggest that it was built up from the debris of animal remains and was not elevated.

Summary

Responds to comments on geology of Florida.

Discusses coral reefs and paper by John Murray ["On the structure and origin of coral reefs and islands", Proc. R. Soc. Edinburgh 10 (1880): 505–18].

Comments on AA’s paper ["Paleontological and embryological development", Proc. Am. Assoc. Adv. Sci. 29 (1880): 389–414].

Summary

Discusses the structure and formation of the Florida peninsula. Part played by marine animals in building banks on which coral can thrive.

Summary

Suggests time for AA to visit.

Summary

Asks whether he may see CD before leaving England.

Summary

Instances of sexual differences in viviparous fishes, suggested by reading chapters on sexual selection [in Descent] and by Mivart’s Genesis of species.

Notes on echinoderms.

Summary

Discusses homologies in various animal groups.

Comments on Mivart [Genesis of species].

Summary

Thanks AA for a ‘splendid case of gradation of structure’.

Summary

Discusses exchange of books.

Summary

Thanks for new [6th] edition of Origin.

Is working on Echini.

The more material he gets the less easy it is to diagnose a genus or species. Has little doubt that "classification is nothing but the most arbitrary convenient tool, depending upon the material at our command at a special time".

Summary

Thanks for Expression.

Has lost a year’s work in the fire that has devastated Boston.