This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Correspondence Ludwig Otto and Engelmann George May verso BHL. Correspondence Ludwig Otto and Engelmann George May verso Illustration Blank Ludwig to Engelmann biodiversitylibrary org Ludwig Otto Permission to digitize granted by rights holder Biodiversity Heritage Library Check categories October PDold books Correspondence