Search: Darwin, C. R. in correspondent 
1870-1879::1872::12 in date 
Maryland Historical Society in repository 
Sorted by:

Showing 12 of 2 items

From:
Charles Robert Darwin
To:
Alpheus Hyatt
Date:
14 Dec [1872]
Source of text:
Maryland Historical Society (Alpheus Hyatt Papers MS 1007)
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.

Contributor:
Darwin Correspondence Project
From:
Charles Robert Darwin
To:
Alpheus Hyatt
Date:
4 Dec [1872]
Source of text:
Maryland Historical Society (Alpheus Hyatt Papers MS 1007)
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.

Contributor:
Darwin Correspondence Project
thumbnail