Felix Klein on Euclid

Reading Felix Klein ... he says of mathematics during the Euclid Era "Several facts have become known only quite recently in this direction. Thus it is now known that the books that have come to us from the time of Euclid constitute only a very small part of what was then in existence;"

Clearly this begs the issue of missing manuscripts ... he talks about Zeuthen and Allman as possibly having some insight into the issue .... IS there a "Black Swan" here?

Probably all missing manuscripts have an aspect of inherent 'Black Swanism" ...