Loose photographs in various size formats, including some in colour.

Where indicated photographs have been refiled from correspondence series for preservation reasons. The link back to original order has been maintained. Some ephemera has been included when it supports the reference back to the photograph's context.

People, places and research topics discussed:

1. Ritter drawings. Schizocardium californicum peruvianum. Ritter originals photocopies comprising 20 sheets 20x26 cm few of which are annotated