An enduring misconception about hackney carriages is that the driver must keep a bale of hay in the boot to feed the (nowadays) non-existent horse. This misconception probably comes about because of section 51 of the
London Hackney Carriage Act 1831 which made it an offence, punishable by a 20 shilling fine, for the owner or driver of a hackney carriage (or any one else) to-
�feed the horses of or belonging to any hackney carriage in any street, road or common passage, save only with corn out of a bag, or with hay which he shall hold or deliver with his hands�.
This offence was repealed by the
Statute Law (Repeals) Act 1976. As a result any taxi driver who travels around accompanied by a bale of hay does so purely for his own amusement and not in compliance with any legal requirement.
Here is the current text (after all repeals) of section 51 of the
London Hackney Carriage Act 1831