H. P. Lovecraft,
The Whisperer in Darkness — Chapter 3
(1931)
“ I hardly need say that I gave that shocking record many another playing, and that I made exhaustive attempts at analysis and comment in comparing notes with Akeley. It would be both useless and disturbing to repeat here all that we concluded; but I may hint that we agreed in believing we had secured a clue to the source of some of the most repulsive primordial customs in the cryptic elder religions of mankind. It seemed plain to us, also, that there were ancient and elaborate alliance; between the hidden outer creatures and certain members of the human race. ”
