Finds no absolute differences in size of sexes of Copridae. Gives several other genera in which males are larger than females.

Confirms his view of stridulation organ of house cricket. [see Descent 1: 354–5.]

Tells CD of a powerful convert to Darwinism: H. von Kiesenwetter of Berlin.

Results of his examination of divergence in sexual coloration of tropical American butterflies. [See Descent 1: 389 on Junonia and Papilio.]

Requests information on the standard of beauty of savages and on whether the female has any influence in selecting a male.

CD has questions related to colour differences in the sexes of butterflies, especially in relation to HWB’s paper ["On variation in sexes of Argynnis diana", Proc. Entomol. Soc. Philadelphia 4 (1865): 204–7].

Mentions that his MS on Lepidoptera [for Descent] is longer than he intended and the information is four-fifths owed to HWB.

In addition to the drawing of a caterpillar which CD intends to use,

HWB sends information on differences of colour and pattern between the sexes of species of Papilio.

Argynnis diana and A. sagana have females that are brightly coloured, but these may be cases of protective mimicry.

Thanks HWB for answering questions.

The MS on Lepidoptera is almost finished and he is glad HWB will read it; he is fearful of mistakes, not being familiar with the subject.

HWB thinks he can buy specimens of male and female insects at Mr Janson’s.

Lists specimens he wants from Mr Janson, emphasising that he always wants male and female.

He extends an invitation for a Sunday in early June.

He has been occupied with Royal Geographical Society anniversary meeting, but did go to Janson and selected various specimens for CD, some of which have remarkable stridulating organs.

The habits of Lethrus are found in Kirby and Spence’s Introduction [to entomology, 7th ed. (1856)].

Because of work on the first number of the new Royal Geographical Society magazine, a manual of geography, and other things, HWB finds he must decline CD’s invitation.

Informs CD of K. G. Semper’s desire to meet him and to discuss new information on volcanic phenomena, geographical distribution, etc.

Ashamed that members of the Entomological Society have almost no information on sex ratio of bred insects in response to CD’s query of months ago. One exception, William Buckler, promises results. [See Descent 1: 313.]

Returns CD’s MS [of entomological section of Descent] marked with suggested alterations.

Suggests qualifications about rudimentary horn in female Onitis furcifer [See Descent 1: 372].

Sends additional data on colour differences in sexes of longicorn Coleoptera [See Descent 1: 367–8].

Suggests a modification of CD’s view of female coloration that would bring him "nearly into harmony" with Wallace.

Concern over Wallace’s book [Contributions to the theory of natural selection (1870)] and its apparent backsliding from Darwinian theory. HWB suggests that only CD is capable of criticising the book.

HWB hopes not too much was made over his few comments on man in M. F. Somerville’s book [Physical geography, revised ed. (1870)].

Explains why he has declined writing a review for Messrs Appleton.

Encloses A. R. Wallace’s reply [in which he says he will undertake revision of Descent if CD wishes]. HWB says this shows that Wallace is unaware of the scope of revision; suggests need for well-defined terms.

Thanks for assistance. He will write fully to Wallace tomorrow.

Orders five works on the Sandwich Islands from the Royal Geographical Society Library for his investigation of infanticide and population trends there.

Books CD requested have been packed and sent.

He will present CD with the classified catalogue [of Royal Geographical Society].

He has not learned whereabouts of Thomas Staley.

Notes that Mr[s] Barber’s communication [forwarded by CD] will be published because of more striking than usual facts ["Notes on … larva and pupa of Papilio nireus", Trans. R. Entomol. Soc. Lond. (1874): 519–21].

Encloses Thomas Belt’s address.