Northern Pike, Esox lucius L., population of Clear Lake, Iowa. Richard L. Ridenhour 1

Growth of bluegill, Lepomis macrochirus, and pumpkinseed, L. gibbosus, of Clear Lake, Iowa. Charles J. Di Costanzo 19

A nonvisual method for transport numbers in pure fused salts. Frederick R. Duke and James P. Cook 35

Effects of nitrogen fertilizer and oat drill-row spacings on agronomic and quality characteristics of oat-legume seedlings. J. G. Wheat, R.E. Atkins, and G.J. Jarvis 39

Damping-off of cotton seedlings caused by Colletotrichum hibisci Poll. H.G. Pulsifer 57

Variation in minimum temperatures on a half-mile slope and their effect on peach trees. R.H. Shaw and C.C. Doll 63

Reproduction an growth of fishes in Marion County, Iowa, farm ponds. Robert B. Moorman 71

The role of chloride ion in the ferric-stannous reaction. A reinterpretation based on new equilibrium data. Frederick . Duke and Norman C. Peterson 89

The effect of the shape of the soil surface profile on soil temperature and moisture. Robert H. Shaw an Wesley F. Buchele 95

Variation on pathogenicity of Diaporthe phaseolorum var. sojae to soybean. John Dunleavy 105