Scotch pine provenance trial in southeast Iowa. G.E. Gatherum and K.F. Jensen. 405

Aerial stand volume tables for Iowa hardwoods. Leland F. Hanks and George W. Thomson. 415

Biology of Stagnospora bromi. Judith H. Mathre. 427

Urinary estrogens in cycling, pregnant, ovariectomized and hysterectomized gilts. A.M. Bowerman, L.L. Anderson and R.M. Melampy. 437

Survey of a life's writing-Paul L, Errington's bibliography. Kenneth D. Carlander and Milton W. Weller. 447

The probability of precipitation at Des Moines, Iowa. Sanford R. Miller. 459

Age and growth of sauger, Stizostedion canadense (Smith), in Lewis and Clark Lake. C. David Vanicek. 481