Thanks RC for "Ice and water" [in RC’s Edinburgh papers (1861)].

Comments on problem of scientific accuracy.

Discusses views of Thomas Davidson on the genealogy of brachiopods.

No summary available.

Thanks TD for his letter. Difficulties with CD’s theory are many and great, but CD thinks the reason is that we underestimate our ignorance. The imperfection of the geological record counts heavily for CD. His greatest trouble is weighing "the direct effects … of changed conditions of life without any selection, with the action of selection on mere accidental (so to speak) variability. I oscillate much on this head, but generally return to my belief that the direct [effects] … have not been great."

Is surprised that any one, like W. B. Carpenter, can go as far as to believe all birds may have descended from one parent, but will not go further and include all the members of the same great division. Such beliefs make "Divine mockeries" of morphology and embryology, the most important of all subjects.

No summary available.

Thanks JM for bill for £480 and sends receipt. Number of copies differs in note and in receipt (2500 and 2000, respectively). Not surprised sale is slackening; number printed was bold. Reminds JM to advertise "with additions and corrections".

Will consult JM on illustrations for Variation.