Gives his opinion that the larval antennae in Lepas correspond with the inferior antennae, the superior not present, as in most Daphnidae. [See 1381.]

Responds to CD’s criticism of his use of word "Kingdom" in discussing geographical distribution of Crustacea.

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

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

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".

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.

Illness has prevented his reading Origin. He has, however, expressed his [negative] opinion on the subject of mutability of species in his Manual of geology [1862]. Since his persuasions are so strong, he can do no less.

Hopes CD has received a copy of his [Manual of] Geology [1862]; justifies his assertion that geology provides no evidence to support the view that life has evolved through a method of development from species to species.

JDD is sending a copy of his book, Corals and coral islands [1872], with his compliments.

Thanks CD for Coral reefs [2d ed. (1874)].

JDD will correct his misunderstanding of CD on one point in the next edition of his book [Corals and coral islands].

Suggests CD consult Charles Wilkes’s Narrative [1844] for more accurate observations on Pacific islands.