From Benjamin Dann Walsh   [25 February 1867]1

insects; in Stainton’s Entom. Annual (1861, p. 39) you will find good proof that worker wasps can & do generate worker wasps.2 The demonstration is simple. A nest containing a single female & several workers is in early spring deprived of the female; & it is found that the building of fresh cells & the production of fresh workers therein goes on as successfully as if the mother-female had remained in the nest. With regard to your ⁠⟨⁠    ⁠⟩⁠

⁠⟨⁠    ⁠⟩⁠ which Dr. Velie assures me never builds a nest for itself, & the books say the same? As with your Cuckoo, the other species belonging to the same genus have no such parasitic habits.3

I enclose you a copy of a recent Lecture by Agassiz, the marked portions in which I thought would interest you. I suspect he has mistaken the deposits left by floating Ice-bergs for true Glaciers. His theory about Glaciers moving on level ground might do for high northern latitudes4 ⁠⟨⁠    ⁠⟩⁠

Editing the Practical Entomologist does undoubtedly take up a good deal of my time, but I also pick up a good deal of information of real scientific value from its correspondents.5 Besides, this great American nation has hitherto had a supreme contempt for Natural History, because they have hitherto believed that it has nothing to do with the dollars and cents. After hammering away at them for a year or two, I have at last succeeded in touching the ‘pocket nerve’ in Uncle Sam’s body, and he is gradually being galvanised into the conviction that science has the power to make him richer. ⁠⟨⁠    ⁠⟩⁠

⁠⟨⁠    ⁠⟩⁠ You cannot have the remotest conception of the ideas of even our best-educated Americans as to the pursuit of science. I never yet met with a single one who could be brought to understand how or why a man should pursue science for its own pure and holy sake.

AL incomplete

1
The date is established by the relationship between this letter and the letter to B. D. Walsh, 23 March [1867].
2
Walsh referred to Henry Tibbats Stainton and to an article on Hymenoptera in the Entomologist’s Annual (F. Smith 1861); the article included a summary of an account of the deposition of fertile eggs by worker wasps presented in Stone 1860, pp. 7263–4.
3
The bird that Jacob W. Velie referred to has not been identified. For a discussion of parasitic nesting habits in birds, for CD’s discussion of the parasitic instinct of cuckoos in Origin, and on his additions to the topic in the fourth edition of Origin, see the letter from Edward Blyth, 19 February 1867 and nn. 18–22. Walsh may be responding to additions in the fourth edition of Origin; CD had sent a copy to him in late 1866 (see Correspondence vol. 14, letter to B. D. Walsh, 24 December [1866]). The species (‘your cuckoo’) that Walsh refers is the common cuckoo (Cuculus canorus); the genus Cuculus now contains sixteen species. For modern cuckoo systematics, see Birds of the world 4: 508–607.
4
The enclosure has not been found. Walsh may be referring to a lecture given by Louis Agassiz at the Cooper Institute in New York in the winter of 1866 and 1867 and published in the New York Herald Tribune (see J. L. R. Agassiz 1867 and E. C. Agassiz 1885, 2: 645); Agassiz also gave lectures at the Lowell Institute in September and October 1866 (Lurie 1960, p. 353). Agassiz returned in August 1866 from an expedition to Brazil, during which he claimed to have seen evidence of glaciation in the basin of the Amazon River (see Correspondence vol. 14).
5
In his letter of 24 December [1866], CD had expressed his sympathy with Walsh over the hard work that he thought was involved in being an editor of a journal (Correspondence vol. 14).

Please cite as “DCP-LETT-5419,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5419