  It is shown that the hole in the centre of $ ^{3}H $, $ ^{3}He $ and $ ^{4}He
$, the neutron halos in nuclei, the $ \alpha - $ and other clustering effects
in nuclei and the nuclear molecules all basically arise due to the same
underlying effect. We shall show that all these ground state properties of
nuclei are manifestations of quark effects. The role of triton clustering in
very neutron rich nuclei is emphasized. All these require the concept of hidden
colour states which arise from confinement ideas of QCD for the multi-quark
systems. This provides comprehensive understanding of diverse nuclear effects
and makes unique predictions.
