To Alpheus Hyatt 13 February 1877
Summary
Regrets that F. Hilgendorf proved so greatly in error ["Planorbis Multiformis", Monatsber. K. Akad. Wiss. Berlin (1866): 474–504; "Noch einmal Planorbis Multiformis", Z. Dtsch. Geol. Ges. 29 (1877): 50–62].
Discusses polymorphic species.
Surprised that shell form developed from various different progenitors.
Reminds CD of C. Nägeli’s conclusions on Hieracium.
But still retains belief expressed in first edition of Origin that variation in protean species is neither advantageous nor disadvantageous.
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 13 Feb 1877 |
Classmark: | Maryland Historical Society (Alpheus Hyatt Papers MS 1007) |
Letter no: | DCP-LETT-10842 |
To Alpheus Hyatt 8 May 1881
Summary
Aware that AH thinks CD has done nothing to advance the good cause of the descent theory.
Obliged for gift of AH’s [Tertiary species of Planorbis at Steinheim (1880)].
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 8 May 1881 |
Classmark: | Maryland Historical Society (Alpheus Hyatt Papers MS 1007) |
Letter no: | DCP-LETT-13151 |
To Alpheus Hyatt 10 October [1872]
Summary
Thanks for "Embryology of the fossil cephalopods", [Bull. Mus. Comp. Zool. Harvard 3 (1872–4): 59–112].
Regrets error in attributing acceleration concept to E. D. Cope instead of to AH in last edition of Origin, and misrepresentation of their joint view.
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 10 Oct [1872] |
Classmark: | Manuscripts Division, Department of Rare Books and Special Collections, Princeton University Library (Hyatt and Mayer Collection Box 2, folder 74) |
Letter no: | DCP-LETT-8551 |
To Alpheus Hyatt 4 December [1872]
Summary
If decapod does not pass through zoea stage, is this acceleration? If hypothetical adult retained zoea characters, would this be retardation? Believes obliteration of growth stages frequently due to natural selection. Most interesting points in AH’s letter deal with senile characters. CD attributes them to laws of growth not selection. Explains degraded characters as result of readaptation to simpler conditions. Believes no innate tendency to progressive development exists.
Hopes AH visits F. Hilgendorf’s famous deposit [at Steinheim]. A. Weismann [Einfluss der Isolierung (1872)] makes good use of Hilgendorf’s observations.
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 4 Dec [1872] |
Classmark: | Maryland Historical Society (Alpheus Hyatt Papers MS 1007) |
Letter no: | DCP-LETT-8658 |
To Alpheus Hyatt 14 December [1872]
Summary
Sends copy of last edition of Origin.
Respecting AH’s theory that acceleration of growth produces new characters, urges AH to examine decapods that do and do not pass through zoea stage. Believes there are no marked differences between them.
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 14 Dec [1872] |
Classmark: | Maryland Historical Society (Alpheus Hyatt Papers MS 1007) |
Letter no: | DCP-LETT-8678 |
To Alpheus Hyatt 21 January [1875]
Summary
Thanks for note and extract.
Will be glad to read AH’s memoir when published [? "The Jurassic and Cretaceous Ammonites collected in South America by Prof. James Orton" Boston Soc. Nat. Hist. [Proc Mem Jnl!?] 17 (1875): 365–72].
Recalls AH’s visit to Down.
Author: | Charles Robert Darwin |
Addressee: | Alpheus Hyatt |
Date: | 21 Jan [1875] |
Classmark: | Maryland Historical Society (Alpheus Hyatt Papers MS 1007) |
Letter no: | DCP-LETT-9826 |