The effect of a honeycomb on a turbulent stream and the turbluence produced by the honeycomb itself are analyzed. The first analysis is similar to the classical one for screens except that: (a) It is assumed that the cell flow is fully developed so that transverse fluctuations are completely annihilated; and (b) both the inertial effect of the mass of fluid in the cell and the effect of frictional resistance are included. The second analysis includes: (a) The turbulence created in the cell flow if the cell flow is turbulent; and (b) the turbulence resulting from the breakup of the wake behind each cell.