From:
Ernst Philipp August (Ernst) Haeckel
To:
Charles Robert Darwin
Date:
10 Dec 1872
Source of text:
DAR 166: 34, 59
Summary:
Thanks CD for Expression.
Describes work on Die Kalkschwämme and its principal conclusions.
The application of biogenetic law.
Notes variability among calcareous sponges.
Gastrula-like "Gastraea" as ancestor of multicellular animals.
Posits homology between Hydra, Olynthus of calcareous sponges, and initial germ layers of higher animals.
Comments on Lubbock’s Prehistoric times [1865]
and on David Strauss’s Der alte und der neue Glaube [1872].
Contributor:
Darwin Correspondence Project