G'day again Barry,

Sorry - esprit de l'escalier - as I submitted the reply, I realised that I should have given a better explanation of the old man plain.

What is meant is "that great big plain" (that I am going to have to cross ... or die trying). The words old man in this sense are Aboriginal / English (Pidgin) for big(gest) so "old man kangaroo or emu" means the biggest kangaroo or emu around ... the biggest ... the boss!

This is an interesting, early, example of Aboriginal usage filtering back into Standard (well, Bush Standard) speech.

Regards,

Bob Bolton