These bull roarers sound curiously uncanny--I did not wonder the uninitiated accepted the spirit theory as to their origin.
The bush of Australia is a good background for superstition; there is such a non-natural air about its Nature, as if it has been sketched in roughly by a Beardsley-like artist.
The function of the Gayandi is to inspire awe, and it fulfils it.
Byamee himself made the first.

It was some time before he got quite the effect he wanted.

At first he desired to give the Boorah spirit a form as well as a voice, to inspire awe; he also wished it to knock out the front tooth of an initiate.
He made a stone figure in the image of man, having a voice.

This spirit, known variously as Gayandi, or Darramulun, went to the Boorah, but when he was to knock out the front tooth, he began to eat the boys' faces.

He was too strong; he would not do to preside over, Boorahs.
Byamee transformed him into a large piggiebillah-like animal, though instead of being covered with spines, thick hair grew over him; he has since been known as Nahgul.