Ɛpsilon

From Robert McAndrew   6 October 1855

Liverpool

6th. October | 1855

My dear Sir

I have received your very kind note of yesterdays date, & beg to say in reply to your first question, that in “typical” I have very probably made use of a wrong word— the forms I allude to are such as Buccinum undatum, & allied species (B. Ciliare, B Humphreysianum, B. Cyaneum, B. Fusiforme &c.)— Fusus Antiquus, F Icelandicus, F propinquus &c.— The Genus Trichotropis—subgenus Margarita— Purpura lapillus— & among bivalves Cyprina Islandica—& the genera Saxicava, Astarte, Leda, Yoldia, Crenella &c.— which are principally develloped in the Arctic Seas, & are considered to be characteristic of these, as the larger Cyprææ, Conus, Voluta, Mitra &c. of the tropical regions.1

With respect to your second question2 I have to state that it has never been my lot to fall in with drift timber—other than what had been used in the construction of vessels, either at sea or upon the Coasts of Britain, though I give no opinion against the statements of its being occasionally washed ashore upon the Coasts of Ireland & of the Western Hebrides—which indeed appears to me highly probable—

I never heard of vessels at sea striking against floating timber other than wreck—& I do not believe that timber ever floats under the surface, though it will after a long time, get saturated with water & sink to the bottom, where if not in too great a depth, it eventually gets destroyed by the Teredo, Xylophaga—Pholades &c.

It will at all times afford me the greatest pleasure to be enabled in any way to assist you in your researches—though my ability for it can be but small—

Believe me always | My dear Sir | Yours most truly | Robt. Mc.Andrew Chas. Darwin Esqr.

1
CD had apparently written to McAndrew after reading his work on the geographical distribution of testaceous Mollusca (McAndrew 1854), an annotated copy of which is in the Darwin Pamphlet Collection–CUL. The gist of CD’s query was reiterated in his annotation on the top of the letter (see CD annotations, above) and refers to McAndrew’s comment in McAndrew 1854, p. 44, that ‘it will appear that several species and forms typical of the Arctic fauna range far to the southward, while scarcely one of those characteristic of warm latitudes extends into high northern regions.’ In his copy of the pamphlet, CD underlined the word ‘typical’ in pencil and noted: ‘does typical here mean common? or belonging to genera which are arctic’. Buccinum undatum is the buckie; B. ciliatum (‘ciliare’ is a misspelling), B. humphreysianum, B. cyaneum (the bluish whelk), and B. fusiforme (a synonym of B. humphreysianum) are similar species. Fusus antiquus is a synonym of Neptunea antiqua, the ancient neptune; F. islandicus(‘icelandicus’ is a misspelling) is a synonym of Colus islandicus, the Iceland whelk; F. propinquus is a synonym of Colus jeffreysianus, Jeffrey's colus. Purpura lapillus is a synonym of Nucella lapillus, the Atlantic dog whelk. Cyprina islandica is a synonym of Arctica islandica, the Iceland cyprina.
2
CD apparently asked McAndrew whether molluscs could be transported across the sea attached to driftwood. At the top of a memorandum attached to his copy of McAndrew 1854, CD wrote: ‘Mr Macandrew told me that some of the Littorina are viviparous. We ought to know how long eggs are hatching— how long larva exist in free state— whether eggs ever attached on old shells to floating weed or drift timber.’ To try to ascertain this point, CD set up a vivarium (see letter to John Lubbock, 24 April [1855]).

Please cite as “DCP-LETT-1759A,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-1759A