  Study on the small-scale structures and material flows of solar quiescent
filaments is very important for understanding the formation and equilibrium of
solar filaments. Using the high resolution H{\alpha} data observed by the New
Vacuum Solar Telescope (NVST), we present the structures of the barbs and the
material flows along the threads across the spine in two quiescent filaments on
2013 September 29 and on 2012 November 2, respectively. During the evolution of
the filament barb, several parallel tube-shaped structures formed and the width
of the structures ranges from about 2.3 Mm to 3.3 Mm. The parallel tube-shaped
structures merged together accompanied with the material flows from the spine
to the barb. Moreover, the boundary between the barb and surrounding atmosphere
is very neat. The counter-streaming flows were not found to appear alternately
in the adjacent threads of the filament. However, the large-scale patchy
counter-streaming flows are detected in the filament. The flows in one patch of
the filament have the same direction and the flows in the adjacent patch have
opposite directions. The patches of two opposite flows with a size of about ten
arcseconds exhibited alternately along the spine of the filament. The velocity
of these material flows ranges from 5.6 km/s to 15.0 km/s. The material flows
along the threads of the filament did not change their direction for about two
hours and fourteen minutes during the evolution of the filament. Our results
confirm that the large-scale counter-streaming flows with the certain width
along the threads of solar filaments exist and are well coaligned with the
threads.
