Sexual differences in reptiles, especially Indian [see A. Günther, The reptiles of British India (1864)].

The Cyprinodontidae family of fishes exhibits sexual differences as remarkable as any in reptiles or birds [Descent 2: 7, 9–10].

Note on sexual differences in Monacanthus.

Sends some questions on secondary sexual differences of fishes [missing], which he hopes AG will look over.

Invites AG to come to Down.

Encloses queries on sexual differences and nest-building habits of fish.

Sends proofs of his fish paper.

Will observe modification of colour in fish.

Is studying the development of the axolotl.

Encloses notes in reply to CD’s queries on fishes.

Sends a list of queries for AG.

Asks whether AG can supply specimens for illustrations [for Descent]. Hopes Mr Ford will do the drawings.

Mr Ford is attending to CD’s drawings [for Descent].

Death of AG’s wife.

Replies to CD’s queries on sexual habits and differences in fish and lizards.

Is glad CD likes the proofs; looks forward to the appearance of his work.

CD should soon receive woodcuts.

R. A. v. Kölliker would much like to visit CD.

Arranges to come to Down with R. A. v. Kölliker.

Sorry to hear of CD’s poor health.

Is hard at work examining Ceratodus.

Encloses discussion of Mus species with functionally prehensile tails.

Encloses argument against freshwater fish entering the sea.

Wants CD’s support for his application for post of Assistant Keeper in Zoological Department of British Museum.

Death of G. R. Gray.

Encloses a testimonial for AG [in support of his application for a promotion at British Museum].

Does he agree with Carl Gegenbaur’s paper on the limbs of fish [Jenaische Z. Naturwiss. 5 (1870): 397–447]?

Asks what caused G. R. Gray’s sudden death.

Thanks for CD’s testimonial.

AG’s application for an appointment to Assistant Keeper at the British Museum.

O. Salvin will not be applying for the same post as AG.

Believes many of the species and even genera of the fish family Labyrinthici are products of domestication.

Events at the British Museum.

Has been appointed Assistant Keeper at the British Museum.

Many thanks for Expression. AG relates some relevant observations, the significance of which had previously escaped him.