Wrote paper on Glaciers of Caernarvonshire.

October:
Began his book on Volcanic Islands.

1843.

Working at "Volcanic Islands" and "some Species work."

1844.

February 13th:
Finished "Volcanic Islands."

July to September:
Wrote an enlarged version of Species Theory.
Papers on Sagitta, and on Planaria.

July 27th:
Began his book on the Geology of South America.

1845.

Paper on the Analogy of the Structure of Volcanic Rocks with that of
Glaciers. "Proc. R. Soc. Edin."

April 25th to August 25th:
Working at second edition of "Naturalist's Voyage."

1846.