They were the "bookies," otherwise bookmakers, generally Jews and sometimes Welshers.
All I said was dat da 'Gink' was for him pulling the bookies.
As for the bookies who hissed the horse on the course—who's to pity them?
If he is satisfied, so are the 'bookies'; and certainly other people have no cause to complain.
The bookies thought that Blinky Bill had sold them, and ...