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].

Thanks CD for comments on Die Kalkschwämme.

Plans trip to Greece, Asia Minor, and Egypt.

Discusses work of a Polish translator, Ludwik Masłowski.

On CD’s paper ["Complemental males of certain cirripedes", Collected papers 2: 177–82].

Comments on paper by W. H. Dallinger and J. J. Drysdale ["Life history of a Cercomonad", Mon. Microsc. J. 10 (1873): 53–8].

Discusses origin of life, the Gastraea theory and concept that primary germ layers are homologous in all animals. Notes similar views of E. Ray Lankester ["On the primitive cell-layers of the embryo", Ann. & Mag. Nat. Hist. 4th ser. 11 (1873): 321–38].

Reception of Darwinism in Germany.

Thanks CD for Descent, 2d ed.

Comments on German edition of CD’s collected works.

Sales of his Anthropogenie [1874] in various countries.

Anticlericalism and progress of Darwinism in Germany.

Discusses his Anthropogenie [1874]. Remarks on the tables.

Has CD received Friedrich von Hellwald’s Culturgeschichte [1875]?

Plans research trip to the Mediterranean.