Has read Origin with satisfaction. He had long ago come to consider the fixity of species as contrary to the facts, but could see no suitable alternative. The Origin has brought the light to guide him.

Sends CD a copy of his latest work ["Mémoire sur la production artificielle des monstruosités", Ann. Sci. Nat. (Zool.) 4th ser. 18 (1862): 243–76]. Hopes to explain a great number of anomalies by his experimental work on artificially produced monstrosities.