Taken from "Things Not Generally Known by John Timbs, David Ames Wells ©1857
Many years ago, men could be easily found to give any evidence, upon oath, that might be required: and some of these persons walked openly in Westminster Hall with a straw in one of their shoes, to signify they wanted employment as witnesses; hence originated the saying "he is a Man of Straw." But the custom has high antiquity. A writer in the Quarterly Review (vol. xzziii. p. 344), on Greek Courts, says: "We have all heard of a race of men who used in former days to ply about our own courts of law, and who, from their manner of-making known their occupation, were recognized by the name of straw sheet. An advocate or lawyer who wanted a convenient witness, knew by these signs where to find one, and the colloquy between the parties was brief. 'Don't you remember? ' said the advocate—(the party looked at the fee and gave no sign; but the fee increased, and the powers of memory increased with it)—' To be sure I do.' ' Then come into court and swear it 1' And straw shoes went into court and swore it. Athens abounded in straw shoes."
Though a straw in the shoe has ceased to be the distinguishing mark, the records of many of our courts show that " men of straw " still exist, and are easily found by those unprincipled enough to require their services. They are now, however, principally employed 09 bail; and " straw bail," has become a familiar word in all our courts. Their false oath of the possession of property is often a ready means of snatching felons from the custody of the law.