A light unstretchable string passing over a smooth light pulley connects two blocks of masses $m _ { 1 }$ and $m _ { 2 }$. If the acceleration of the system is $\frac { g } { 8 }$, then the ratio of the masses $\frac { m _ { 2 } } { m _ { 1 } }$ is :\\
(1) $8 : 1$\\
(2) $5 : 3$\\
(3) $4 : 3$\\
(4) $9 : 7$