No need to apologise for not quoting AH’s paper on acceleration and retardation.

Agassiz introduced AH to ammonites and entrusted collection to him. Has followed developmental history of each species and placed them within geological formations. Found evolutionary history of species recapitulated only to a degree in individual development. Stages frequently skipped. Explains why young of later animals are like adults that preceded them. Retardation entirely idea of Edward Drinker Cope. Sends paper to explain it. Acceleration can explain degraded forms. Often like youthful stage with which series began. Often resemble old age of earlier series. Regularity of these series incompatible with natural selection. How can selection account for degraded final stages or for predictability of development? Franz Hilgendorf’s Paludinae from Steinheim lake show same parallelism in development. May be possible to reconcile this with selection. But Trochiformis begins to show degradation in beds where it is most numerous and has largest individuals, i.e., where selection seems to be favouring it. Will work on Steinheim shells this winter.

Is delighted to receive expression. Some comments on swallowing and scratching. Asks to be sent reviews.

Thanks for copy of Expression.

Reminiscences of their youth.

Sends CD a copy of the second part of his paper on the remains and antiquities of Olmütz in Moravia.

A number of students wish to nominate CD as Lord Rector of the University of Aberdeen and JSC inquires whether CD’s state of health would prevent his standing as a candidate.

Has received Expression and will forward it to his brother [Jean-Charles Houzeau de Lehaie].

Asks CD’s opinion of John Denny’s idea that males have prepotent transmission power in plants. A. J. F. Wegmann says the females are prepotent.

Observations on expression: women gnash teeth when sexually excited. W. Africans do not kiss.

Has finished reading Descent and sends some comments [missing].

Thanks for Expression.

Is convinced that 2000 more copies [of Expression] must be printed without delay in order to meet demand. He therefore asks CD to send his corrections to the printer at once.

Sends thanks for Expression; offers some additions, and will send printed queries abroad if CD wishes.

Thanks for CD’s photograph, which recalls the Charles Darwin of olden days.

Has been asked to take shares in the Artizans’ Dwellings Co., in which CD is a shareholder. If it is really a project for public good, he would be glad to be associated.

Owen has answered his letter in Nature [7 (1872): 5–7].

A letter from Tyndall [from America] was read at the X Club.

Writes, as a P.S. to his previous letter, stating his friends have advised him not to answer Owen’s attack.

Thanks for copy [of Expression].

Has now read Charles Bell’s book [Anatomy and philosophy of expression, 3d ed. (1844)].

Reports instance of person, blind from birth, frowning, when supposedly the blind cannot control the muscle required.

The reception of Expression has exceeded even JM’s expectations; 5267 copies were sold at the annual sale. CD’s modesty about the work had misled him about its probable sale.

Going on circumnavigation voyage aboard the Garibaldi.

Praise for Expression.

Price of Expression is 12s.

Sends cheque to pay CD his share of profits on Origin [6th ed.].