From Edward Forbes [9 May 1845]1
Friday.
Dear Darwin
I have been too busy to look over your list with requisite consideration until yesterday.
I have marked on the lists their probable depths judging from the associations of the genera.2 My marks are within wide ranges.
I could come however to more likely conclusions were two points noted
1st—the average size of the specimens & species found in each locality.
2d The comparative abundance of specimens of each species, & their state, as indicating life & death &c
Thus the Huafo list might indicate twice the depth if the species are all very small & the specimens of Turritella few.
All such calculations, at any rate, must be only provisional, until we know the range in Depth of mollusca in the neighbouring seas.
Footnotes
Bibliography
South America: Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy RN, during the years 1832 to 1836. By Charles Darwin. London: Smith, Elder & Co. 1846.
Summary
Has marked probable depths of the specimens on CD’s list of S. American shells. Asks for details which would provide more precise conclusions. [See South America, p. 226.]
Letter details
- Letter no.
- DCP-LETT-866
- From
- Edward Forbes
- To
- Charles Robert Darwin
- Sent from
- unstated
- Source of text
- DAR 43.1: 50
- Physical description
- inc †, CD list 4pp † (by EF)
Please cite as
Darwin Correspondence Project, “Letter no. 866,” accessed on 24 April 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-866.xml
Also published in The Correspondence of Charles Darwin, vol. 3