Thanks for copies of the Proceedings of the Geological Society of London, with a request for items (listed) missing from their set.

Offer to supply, if they can, any copies missing from the Geological Society’s run of the American Journal of Science.

On the suggestion of Jeffries Wyman, he writes about the rats that he captured in Mammoth Cave in 1850. They were indeed blind. Reginald Mantell studied them and learned that with long exposure to graduated light, they became somewhat sensitised. Sends copy of an abstract which he wrote as a letter to A. H. Guyot ["On the Mammoth Cave of Kentucky", Am. Journal of Sci. and Arts 2d ser. 11 (1851)]. [See 3007.]