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Darwin Correspondence Project

From Erasmus Alvey Darwin   [May–June 1858]1

Dear Charles.

The obtuse ∠ of the Dodec,2 placed with its axis vertical call its highth above the horizontal plane
h = side of hexagon of bees cell 1.414 = 0inch.125 1.414 = 0.088 diagram


It has not been possible to date the letter more precisely: in May 1858 CD reported that he had ‘settled’ his theory of the construction of bees’ cells (see letter to W. E. Darwin, 14 [May 1858]); but in June he was still investigating the geometry of cells (see letter to W. E. Darwin, [26 May 1858], and letters from E. A. Darwin, [before 8 June 1858], [8 June 1858], [after 8 June 1858], and [19 June 1858]).
This letter and subsequent letters on the problem show that CD was seeking to confirm that the geometry of hive-bees’ cells, which may be regarded as hexagonal prisms with pyramidal bases comprising three rhombic plates or as stretched rhombic dodecahedrons, could naturally arise from the compression and extension of spheres arranged in a honeycomb pattern. See also letter to W. H. Miller, [15 April 1858].


Calculations relating to bees’ cells.

Letter details

Letter no.
Erasmus Alvey Darwin
Charles Robert Darwin
Sent from
Source of text
DAR 48: B18
Physical description
AL 1p

Please cite as

Darwin Correspondence Project, “Letter no. 2195,” accessed on 1 June 2023,

Also published in The Correspondence of Charles Darwin, vol. 7