To John Lubbock   [before 5 February 1861]1

[Down]

Saturday night

My dear Lubbock

Your paper seems to me very clear & interesting.2 The subject is too deep for me to offer any remarks. Except indeed to raise my voice in highest tone against your quoting difficult German passage. Surely you ought to translate them; otherwise they will be skipped by 99 out of 100 readers.—3

I hardly know what to say or think about your concluding speculations. I should grieve to see them struck out; & such speculations always call vivid attention to any facts. Yet they seem rather bold & to rest on scanty basis.— I fear that they might lead the old sober coaches to call you rash.—4

Yet I daresay if I had written them myself, I shd have been enamoured with them & would not have given them up for any body. The passage on last long page seems somehow rather less bold than the actually concluding sentences. On last long page do you not leave impression that difference in eggs does go with agamogenesis?5 All I can say is that I am loth to see so fine a speculation cancelled at present, yet I tremble for you.—

Yours affectly | C. Darwin

The date is based on the reference to Lubbock 1861b, which was received by the Royal Society of London on 5 February and read on 21 February 1861.
The reference is to Lubbock’s detailed, histological study of the formation of the egg cell in various groups of invertebrates (Lubbock 1861b). The work resulted from a continuation of Lubbock’s research into the processes of asexual reproduction in various insect groups. In two previous publications (Lubbock 1857 and 1859), he had described the two different kinds of eggs (agamic and true ova) found in Daphnia and other genera that reproduce parthenogenetically. In Lubbock 1861b, he showed that insect species that reproduce sexually also exhibit two different types of egg development, and hence that the phenomenon was not unique to organisms exhibiting parthenogenesis (Lubbock 1861b, p. 624).
In the printed paper, Lubbock translated into English all passages cited from the works of German authors.
CD probably refers to Lubbock’s speculation, in the concluding remarks of Lubbock 1861b, that the existence of two different kinds of spermatozoa in several invertebrate species might provide a key to the problem of sex determination. He posed the question ‘whether the two sorts of spermatozoa produce embryos of different sexes.’ (Lubbock 1861b, p. 625). The process of fecundation (fertilisation), in particular the extent and manner of interaction between male and female elements, was a subject of great debate at the time. See Farley 1982.
In both Lubbock 1857 and 1859, Lubbock had stated that there was no essential difference between the agamic eggs and the true ova of various insects (see Correspondence vol. 6, letter to John Lubbock, 27 October [1856]; and vol. 7, letter to John Lubbock, [November 1858]). In Lubbock 1861b, p. 624, Lubbock accentuated the histological differences that he found between the two kinds of eggs, stating that ‘throughout the Annulosa there are two sorts of eggs, which are of an essentially different structure, and cannot, therefore, strictly speaking, be regarded as homologous with one another.’ For contemporary naturalists, Annulosa comprised all the segmented animals, namely Crustacea, Mryriapoda, Arachnida, Insecta, and Vermes. Today these animals are classified within the phyla Arthropoda and Annelida. In modern usage, Annulosa is sometimes mentioned as a less preferred alternative name for Annelida (Rothschild 1965).

Manuscript Alterations and Comments

2.3 bold] after del ‘bol’
3.5 is] interl

Please cite as “DCP-LETT-3038,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-3038