I can muddy the waters...

According to editor E. Scholz of Hausdorff’s [*Collected Works*](http://www.ams.org/mathscinet-getitem?mr=2478457) (2008, [p. 884](https://books.google.com/books?id=zlmJIO02NlsC&pg=PA884)):

>In a note of 3/20/1933 (*Nachlass*, fasc. 449) and in a further undated note (fasc. 571), Hausdorff symbolized the functoriality property of homology (in our later terminology) with a commutative diagram of homomorphisms between the terms of two sequences of groups $(A_n)_{n\in\mathbf N}$, $(A'_n)_{n\in\mathbf N}$:
 
![commutative diagram](https://i.sstatic.net/aIfaX.png)
>(*Nachlass*, fasc. 571, leaf 1).

Could this have, somehow, made its way out of Bonn where Hausdorff lectured on combinatorial topology that year?