subs. phr. (common).1. Usually THE WHOLE BAG-OF-TRICKS = every shift or expedient. [See fable of The Fox and the Cat.] Hence THE BOTTOM OF THE BAG OF TRICKS (or THE BAG) = a last resource; a card up ones sleeve.
1659. REYNOLDS [BURTON, Diary (1828), iv. 447]. If this be done which is IN THE BOTTOM OF THE BAG, and must be done, we shall be able to buoy up our reputation.
2. (venery).The penis and testes.