searching for source of quote of von Hofmannstahl

[Warren Linds]

In Italo Calvino's Six Memos for a new millenium he quotes Austrian poet and dramatist (and co-founder of the Salzburg Festival) Hugo von Hofmannstahl as having written/said,

"Depth is hidden. Where? On the surface".

Calvino doesn't provide any further reference and many searches on google.com and other search engines have only turned up the Calvino quote and not the reference to the original. (I did check his well-known Letter to Chandos but it wasnt there either) Does anyone familiar with von Hofmannstahl know where this quote came from in his writing (either in German or English translation) or where I might go to look? Thanks in advance.

Warren Linds
UBC