Statistical summaries are presented of computed values of parameters appearing in a modification of Sutton's diffusion equations. Experimental data used for the computations are those obtained during Project Prairie Grass at O'Neill, Nebraska and those obtained at Round Hill, Massachusetts. Stratification of the parameters ny and nz according to stability class reveals systematic variations of class-median values of ny and nz with stability class and a large range of ny and nz within any given stability class. No difference in the results was found between the two sets of experiments for these parameters. The parameter, Cy, has a mean value of about 0.4 for the Prairie Grass experiments and about 0.9 for the Round Hill experiments. No relationship between Cy and stability was found for the Prairie Grass experiments, but a correlation coefficient of 0.22 between Cy and stability ratio was found for the Round Hill experiments. The parameter, Cz, computed only for the Prairie Grass experiments, has a mean value of about 0.07 and is independent of stability for those experiments permitting a statistically-stable estimate of Cz.