The deleterious substance responsible for the death of the soybean plants attempted to be grown in the greenhouse during the fall of 1937 and spring of 1938 was zinc which had dissolved from the nutrient solution pump. There exists a distinct varietal variation among soybeans in reaction to approximately 0.3 p.p.m. (2.3 mgms per plant) of zinc in a slightly acid nutrient solution when plants are grown in crushed quartz. Hudson Manchu will successfully tolerate 8 andperhaps 12 times the external concentration of zinc as will Peking. The mechanism of varietal reactions of soybeans to zinc was not determined, although differential absorption and tolerance are discussed in this connection. The reaction of soybean varieties to zinc showed no correlation to percentage of oil or protein of the seed. Likewise, there appeared to be no consistant relationship between color of seed and plant reaction to zinc. Among the varieties studied, with the exception of Biloxi and Virginia, early maturity and resistance and late maturity and susceptibility appear to be associated. Also, with regard to size of seed and varietal reaction to zinc, it may be stated that the most resistant varieties were the largest seeded ones, while the most susceptible varieties were the smallest seeded ones.

The moisture, carotene, crude protein, crude ash, calcium, and phosphorus content of buffalo grass (Buchloe dactyloides) and blue grama (Bouteloua gracilis) have been determined at intervals during the period from May, 1939, to November, 1941. Moisture, crude protein, carotene, and phosphorus were high in both grasses during the early stages but decreased rapidly as the plants approached maturity. Calcium was quite variable in both varieties throughout the growing season. The average of analyses of all samples taken after frost showed buffalo grass to be much higher in crude protein, crude ash, calcium, and phosphorus than was blue grama. This has been interpreted as indicating that buffalo grass makes better winter pasture and suffers less loss of nutrient material as a result of wintering or leaching than does blue grama. The chemical composition of buffalo grass seems to be affected less by previous clipping than that of blue grama. As a factor in pasture management for the Southern Great Plains area, the effect of frequency or intensity of grazing on chemical composition may be insignificant in comparison with the effect of the variability of weather conditions and grazing on total yield of grass.