e Common Law, however, have not been reduced to writing, save in so
far as they are contained in reports, legal opinions, and, more
particularly, authoritative decisions of the courts, such as those (p. 043)
on the rights of jurymen, on the prerogative of the crown, on the
privileges of the houses of Parliament and of their members, and on
the rights and duties of the police.

*43. Constituent Elements: the Conventions.*--Finally, there are those
portions of the constitution which have been denominated with aptness
by Mr. Dicey "the conventions."[48] The "law" of the constitution,
comprising the four categories of elements which have been enumerated,
is at all points, whether written or unwritten, enforceable by the
courts; the conventions, although they may and not seldom do relate to
matters of vital importance, are not so enforceable. The conventions
consist of understandings, practices, and habits by which are
regulated a large proportion of the actual operations of the
governmental authorities. They may have acquired expression in written
form, but they do not appear in the statute-books or in any instrument
which can be made the basis of action in a court of law. For example,
it is a convention of the constitution which forbids the king to veto
a measure passed by the houses of Parliament. If the sovereign were in
these days actually to veto a bill, the political consequences might
be serious, but there could be no question of the sheer legality of
the deed. It is by virtue of a convention, not a law, of the
constitution, that ministers resign office when they have ceased to
command the confidence of the House of Commons; that a bill must be
read three times before being finally voted upon in the House of
Commons; that Parliament is convened annually and that it consists of
two houses. The cabinet, and all that the cabinet, as such, stands
for, rests entirely upon convention. To these things, and many others,
the student who is concerned exclusively with the constitutional law
of the British nation may give little or no attention. But by one who
is seeking to understand the constitutional system as it is and as it
operates attention must be fixed upon the conventions quite as
steadily as upon the positive rules of law. If the conventions are not
to be regarded as technically parts of the constitution, they are at
least not infrequently as binding in practice as are these rules; and
they may be even more determinat