| Signature mark | NL 174/1395 |
|---|---|
| Subject | Brief |
| Author |
Haeckel, Ernst
|
| Recipient |
Mach, Ernst
|
| Title | Haeckel, Ernst an Mach, Ernst |
| Places | Jena |
| Duration | 04.02.1907 |
| Scope | 1 S. hs. |
| Rights notice | CC BY-SA 4.0 |