On the possible existence of crystallites in glass-forming liquids
  We speculate that glass-forming liquids may contain fairly large and well-defined crystallites. This is based on arguing that the slowly relaxing "frozen-in" stresses characterizing ultraviscous liquids increase the barrier for nucleation, thus allowing for larger unstable crystallites than otherwise possible. The frozen-in stresses also deform the crystallites, making their observation difficult; specifically it is argued that a situation where 1/N of the molecules form N X N X N crystallites would be hard to detect by standard X-ray or neutron scattering experiments. 
Jeppe C. Dyre