Summary

Asks whether the blind cave animals described by B. Silliman Jr [Am. J. Sci. 2d ser. 11 (1851): 332–9] belong to genera found only on the American continent.

On geographical distribution of Crustacea, CD asks whether northern genera sent species to the Southern Hemisphere or did southern genera send species north?

Does he know of any author who has described fossil trees in South Shetland Islands?

Summary

Thanks for sending paper on geological development (Dana 1856). Discusses infertility of species. Discusses first part of Asa Gray’s paper (A. Gray 1856–7). Thanks for note on the Cave Rat. Discusses a new species of fossil cirripede, in the genus Chthamalus. Explains his interest in pigeon breeding.

Summary

Thanks JDD for replies to queries [in 1925]; would like to know whether teeth of cave rat are of New or Old World type.

Wishes Louis Agassiz would publish his theory of parallels of geological and embryological development. "I wish to believe but have not seen nearly enough as yet to make me a disciple."

Is working hard on variations and origin of species, but fears it will be a couple of years before he publishes.

Describes his recent work on rabbits and pigeons.

The dispersal of land Mollusca is a most difficult problem.

Confesses he is sceptical of immutability of species; discusses difficulty of proving it.

Summary

Asks whether Crustacea from temperate parts of the Southern Hemisphere are more strongly analogous to those in same latitudes of the Northern Hemisphere than are Arctic to Antarctic Crustacea.

Discusses astonishing finds of mammalian and reptilian remains in Purbeck beds; notes reactions of Lyell.

Has doubts about Richard Owen’s recent classification of mammals [J. Proc. Linn. Soc. Lond. (Zool.) 2 (1858): 1–37].

Works away [on Natural selection].

Asa Gray has given valuable assistance.

Summary

Thanks him for information concerning Crustacea.

Comments on natural history study in the U. S.

Mentions work done by Huxley on Crustacea ["Description of a new crustacean", J. Geol. Soc. Lond. 13 (1857): 363–9];

John Lubbock on larvae of Diptera.

Summary

Responds to CD’s query about the blind fauna of Mammoth Cave.

Gives information from L. Agassiz. Distribution of Crustacea, especially along southern coastlines.

Summary

Agassiz has informed him that the mice and rats of Mammoth Cave are American in type.

Alludes to CD’s doubt of the principle that "progress of life on the globe is parallel with the development in different tribes". Outlines his own ideas on the "unfolding of the type-idea" and its "parallelism with the law of development in the embryo".

Summary

In reply to CD’s query [see 2072], JDD describes what little is known about the crustacea of the Antarctic and southern lands.

Knows of no species of the cold temperate south identical with those of the cold temperate north.