Small quantities of soil humic acids were supplied to cultures of Nostoc muscorum, resulting in stimulation of growth and nitrogen fixation. Various organic compounds were added to compare stimulations and structural relationships. Of all the compounds tested, catechol and humic acids were found to give the greatest increases of nitrogen fixed. Part of the increase in nitrogen fixation was thought to be due to boron contained by the humic acids. Lignin oxidized by H₂O₂ and microorganisms was analyzed by infrared spectroscopy. The product formed by microorganisms gave a material with similar paper electrophoretic mobility as natural humic acids. Controlled degradation of humic acids and lignin gave various phenols. Humic acid chromatograms showed four phenols present: catechol, phenol, guaiacol, and o-cresol. One spot found in the humic acid chromatograms has not yet been identified. Bean root lignin when subjected to the same degradation gave a spot in the same position and with the same color. Guaiacol and phenol were also identified from bean root lignin.

Infectious coryza, a respiratory disease of chickens, is caused by the bacterium Haemophilus gallinarum. The disease has continuously plagued sections of the poultry industry in California for a number of years. Since prevention and control measures have met with relatively little success, new approaches have been made to the study of the disease. Haemophilus organisms associated with recent field cases of coryza and airsac disease have been isolated and characterized for their cultural aspects, biochemical activities, specific antibodies formed against them, and their virulence in causing disease in chickens, chicken embryos, and mice. Similar studies have been made on other microorganisms found associated with H. gallinarum in diseased tissues, especially members of the genus Pasteu-rella. Whether the severe disease observed in field cases was caused by H. gallinarum alone or by a combination of agents is under investigation.

A photomicrographic study was made of the soil at the surface of stubble-mulched and plowed soil plots on July 7, August 28, and October 22, 1959. These soils had been subjected to stubble mulching or plowing for a 20-year period. The plots were in corn in 1959 following wheat in 1958. The surface of the stubble-mulched soil had larger soil aggregates and voids than plowed soil. Contact slides placed in the plots showed more microorganisms on stubble-mulched than on plowed soil. Water-stable aggregates from each type of tillage were also embedded in plastic compounds. These aggregates were sliced in sections 30 and 0.2µ thick and photomicrographed with light and electron microscopes, respectively. A major problem was the impregnation of soil aggregates for sectioning. The cross-sections of aggregates from stubble-mulched plots seem to be less compact and more porous than from plowed plots in both the 30 and 0.2µ sections of soil aggregrates.