Is slaving at South America – ¾ finished.

Has discovered geologists never read each other’s works – "the only object in writing a book is a proof of earnestness … Geology is at present very oral".

Has nearly finished South America.

Pleased to hear JDH has worked out identical and representative species of N. Temperate and Antarctic regions.

Geoffroy Saint Hilaire’s "loi du balancement" as applied to plants.

CD jaded by, but has nearly completed, South America.