The reproductive success of sibling cocklebur plants (Compositae: Xunthium strumarium) was monitored after growth at different levels of availability of water and nutrient resources. Variation in reproductive success among individual plants was related to physiological, structural, and phenological characteristics. Reproductive success increased with increased availability of resources, but the...

Proc. Amer. Soc. Hort. Sci. 55: 247-253. 1950. 27. SCHAEFER, V. J. The formation of ice crystals in the laboratory and the atmosphere. Chem. Rev. 44: 291-320. 1949. 28. SCHOONOVER, W. R., BROOKS, F. A., and WALKER, H. B. Protection of orchards against frost. California Agr. Ext. Circ. No. 111. 1939. 29. SEEMANN, J. tJber die Bedeutung der Unterkiihlung fur die Selektion frostresistenter Bohnenp...