Estimation of consecutive dry days at Ames and Corydon, Iowa. R.E. Myers and R.H. Shaw. 1

Some aspects of the life history of the carp, Cyprisus carpio, in the Des Moines River, Boone County, Iowa. Dudley Dean Rehder. 11

Effect of sanitation, packaging, and antibiotics on the microbial spoilage of commercially processed poultry. John C. Ayers. 27

Cultural factors in seedling vigor of smooth bromegrass and other forage species. R.R. Kalton, R.A. Delong, and D.S. Mcleod. 47

Evaluation of various methods and reagents for total hardness and calcium hardness in water. Charles A. Goetz and Robert C. Smith. 81

Mechanisms of carbon dioxide fixation by cell-free extracts of heterotrophic and photosynthetic bacteria. C.L. Baugh. T. Myoda, D.S. Bates, and C.H. Werkman. 113

Index to Doctoral Theses, 1957-58. 119