Seitz, W.K., and R.B. Dahlgren. Water-based recreational use patterns of the upper Iowa River. 131

Bennett, D.F. and A.J. Netusil. Comparison of competencies needed by selected entry level employees in leisure services. 147

Ellis, C.J. and P. Thome. Syringeal histology, IV. Parulidae: ovenbird, Seiurus aurocapillus, and mourning warbler, Oporonis philadelhpia. 153

Hall, J.L., W.W. Bathie, D. Van Meter, and J. Herrin. Exhaust emission comparisons and statistical analysis by use of leaded and nonleaded gasolines in a large vehicle fleet. 173

Carlson,R.E., and T.E. Fenton. Remote sensing of Iowa's agricultural resources by using the ERS-1 satellite. 189

Glass, L.W. Content preparation of biology, chemistry, and physics teachers in Iowa public high schools. 209

Guthrie, W.D., W.A. Russell, F.L. Neumann, G.L. Reed, and R.L. Grindeland. Yield losses in maize caused by different levels of infestation of second-brood European corn borers. 239

Herman, R.P., and C.L. Kucera. Vegetation management and microbial function in a tallgrass prairie. 255

Jabin, S., and J.N. Farmer. Passive transfer of heterologous immunity in avian malaria. 261