Quark Spin Properties at High x

A general three quark bound state satisfying the Pauli principle, and conserving angular momentum and isospin, is used to investigate the spin structure of nucleons at high $x$. It is shown if {$F_{1n}/F_{1p}$$\to$1/4}, then both $A_{1p}$ and $A_{1n}$, as well as quark spin distribution $\Delta u/u$, will approach 1 as $x$$\to$1 in polarized deep inelastic scattering. The spin distribution $\Delta d/d$ does not approach 1, but is bound by the limits $-{1/3}\le\Delta d/d\le 0$ for any $x$.