  It is shown that a relativistic (i.e. a Poincar{\' e} invariant) theory of
extended objects (called p-branes) is not necessarily invariant under
reparametrizations of corresponding $p$-dimensional worldsheets (including
worldlines for $p = 0$). Consequnetly, no constraints among the dynamical
variables are necessary and quantization is straightforward. Additional degrees
of freedom so obtained are given a physical interpretation as being related to
membrane's elastic deformations ("wiggleness"). In particular, such a more
general, unconstrained theory implies as solutions also those p-brane states
that are solutions of the conventional theory of the Dirac-Nambu-Goto type.
