A chemical and biological evaluation of nine MG clones shows that: 1. No significant differences were found in yield of root, but there is a strong indication that clone 9 is the best in root production. 2. Clones 1, 2, 3, and 4 were consistently better than the remaining clones with regard to quality of root based on percentage rotenone. 3. There was a significant correlation between the percentages of rotenone and rotenone plus rotenoids with biological toxicity (rotenone equivalent). The correlation between total chloroform extractives and rotenone equivalent was highly significant. 4. The average yield of rotenone for the nine clones was about one-half the yield of toxicity, as determined by bio-assay. 5. The best clones in the group, based on the amount of toxicityper plant as determined by the guppy test, were 1 and 9.

Within the limit of a grape vine's capacity to bear fruit, the date of ripening is determined mainly by heat and can not be hastened by a reduction in crop.

A chemical and biological evaluation of nine MG clones shows that: 1. No significant differences were found inyield of root, but there is a strong indication that clone 9 is the best in root production. 2. Clones 1, 2, 3, and 4 were consistently better than the remaining clones with regard to quality of root based on percentage rotenone. 3. There was a significant correlation between the percentages of rotenone and rotenone plus rotenoids with biological toxicity (rotenone equivalent). The correlation between total chloroform extractives and rotenone equivalent was highly significant. 4. The average yield of rotenone for the nine clones was about one-half the yield of toxicity, as determined by bio-assay. 5. The best clones in the group, based on the amount of toxicity per plant as determined by the guppy test, were 1 and 9.

The occurrence of Azotobacter chroococcum and Clostridium spp. has been determined in a number of cultivated and virgin Queensland soils, representing a wide range in soil characteristics. There was no indication that Azotobacter occurred more frequently in virgin than in cultivated soils. Anaerobic species of Clostridium were found constantly in Queensland soils.

The empovrishment of the soil brought about by erosion and cultivation of cotton has been studied in experimental plots where catch tanks were employed to collect soil removed by erosion. These tests have been carried out by the Soil Conservation Department at the Experiment Station of the Instituto Agronômico of Campinas, in Pindorama, and on the "Arenito Bauru" soil type representative of the region. Actually sixty percent of all coffee and eighty percent of all cotton cultivation in the State of São Paulo is on the "Arenito Bauru" soil type. Thus the data collected, although preliminary, are of great interest, and indicate that the empovrishment of the "Arenito Bauru" soil by erosion is extremely rapid. It is also pointed out that the "Arenito Bauru" soils are the most highly erodable of all soil types in the State of São Paulo. A chemical analysis was made of representative samples of the original soils in the experimental plots and of samples of soil carried in the runoff, for the purpose of determining the losses due to erosion. It has been determined that the soil transported in the runoff is proportionally very much richer in mineral elements than was the original soil. The data obtained from analysis of samples showed that soil eroded from the experimental plots contained 2.0 times as much organic material, 2.8 times as much P2O5 ; 2.3 times as much K2O, and 1.9 times as much CaO, as was determined present in the samples obtained from the original soil of the experimental plots. In the runoff water it has determined that calcium was present in larger quantities than other elements. On the basis of data obtained from the experimental plots with cotton cultivation, an evaluation and comparison was made of the amount of mineral elements lost by erosion and the amount used by the cotton crop. It was found that the empovrishment of the soil by loss of organic material and chemical elements was due more to erosion than to utilization of these in the production of harvested cotton. A discussion is given of forms of organic and mineral fertilizers to be employed on "Arenito Bauru" soils, taking into consideration the physical and chemical nature of these soils.

Stands of alfalfa, determined by the number of 6-inch gaps in drill-seeded rows, were shown to be highly correlated with yields obtained in the first 2 years from seedings of the 1946 regional uniform alfalfa nursery. It appears that this method is desirable for the determination of stand differences. The influence of stand on yield was greater in the first than in the second year after seeding and is attributed to the ability of alfalfa partially to adapt to thin stands. Under the conditions encountered during the two years of this test, sampling each harvested plot for percentage dry matter in order to determine yield at a specified dry matter content appeared to be unnecessary.

Two single-cross hybrids, WF9XHy and K4XL317, were grown in alternate rows in small plots with different treatments of fertilizer and water at Urbana in 1947. The yields of grain and stover and their nitrogen composition were determined for each hybrid within each plot. In this experiment, it appeared that K4XL317, in competition with WF9XHy, did not yield as well under unfavorable conditions and that it responded more to water than WF9XHy. Stover of K4XL317 was higher in nitrogen than that of WF9XHy, but the difference in nitrogen content of the grain was not significant. Both hybrids responded to the nitrogen, water, and the combination phosphorus-potassium-minor element soil treatments.

1. The active cardiac principle of Urginea rubella Baker has been isolated. Analysis points to the empirical formula C₃₆H₁₈O₁₆. The name suggested for this compound is "rubellin". Rubellin melts at 261-3°C. with decomposition and has [α]27/D = 15.81°(MeOH). 2. Hydrolysis of rubellin yields a sugar and pro-rubillidin, having M.P. 267-8°C. (decomp.) and [α]20/D = 24°(MeOH). 3. Succinic acid was isolated in small yield from the plant. 4. The toxicity of rubellin towards white rats was determined by intraperitoneal injection, the L.D.50 being 0.692 mgm. per Kg. Dosed to rabbits per os, the toxicity of rubellin is about 10 mgm. per Kilogram rabbit.

The incomplete T-curve has been fitted to frequency distributions of n-week rainfall totals. The parameters in this equation were estimated by the method of maximum likelihood. This curve, when checked against the frequency histograms by the chi-square test, showed a good fit in most cases. Only when the frequencies exhibited a definite bi-modal tendency were the chi-square values greater than would be expected from random fluctuation. More years of record would probably erase much of this tendency. From the probability integrals of the fitted curves the likelihood of occurrence of a certain class interval of n-week rainfall totals can be estimated for each station. The probabilities of like amounts, x(a), or less for giver durations at each station have been computed and, likewise, the probabilities of the proper base amounts, x(d) or less (different for each station) have been estimated. These probabilities afford a basis for comparison of different areas with regard to rainfall distribution alone and also with regard to the likelihood of receiving the minimum amount of precipitation needed to produce a normal corn crop. Similarly, the probability of occurrence of any class of rainfall totals could be determined; e.g., the probability of receiving between 8.0 and 10.0 inches of precipitation at Ames during the 3-week period beginning July 5 could be estimated. The use of the distribution function is by no means limited to the drought problem. The probabilities determined point to distinct differences in the drought hazards experienced at various stations. Southern Iowa, while enjoying a rainfall contingency comparing favorably with other areas in the state, has rainfall requirements so high that drought is much more likely in the southern counties than in the central and northern sections. While less pronounced, western Iowa presents more of a drought problem than does the eastern part of the state. It is supposed that soil characteristics and evaporation conditions are responsible for the greater needs of the southern and western counties.

1. The effect of season on variation in oil content of the corn kernel is shown to be small in comparison to the effect of parentage. 2. Data are presented from four crosses between inbreds differing in oil content. Two of the crosses show partial dominance of low-oil content, a third is intermediate, and the fourth cross exhibits some evidence for dominance of high-oil percentage. 3. The relative effects of percentage of germ in the corn kernel and percentage of oil in the germ on the total oil content of the kernel were determined. 4. Inheritance of oil content in a cross between HO and LO, inbreds derived from the Illinois High-Oil and Illinois Low-Oil strains, is discussed with reference to type of gene action and minimum gene numbers involved.