Rates and energies of consumption (C), egestion (F), assimilation (A), respiration (R), growth (Pg), production of exuviae (Pev), and production of egg masses (Pr) and associated efficiencies, and the effects of seasonal temperature, weight and metamorphic stage upon these factors were examined for a typical individual and cohort of Corydalus cornutus (L.) from a stream in North-Central Texas (330 23'N, 97*5'W). Dobson flies are apparently univoltine in the study area, with 11 larval instars. Emergence, oviposition and hatching occur from late May to August. The typical dobson fly hatches in mid-June, grows rapidly until November, and resumes rapid growth in March, reaching full adult size prior to leaving the stream to pupate in early June. Adult females must feed to provide energy to yolk eggs, produce egg-mass coverings and continue somatic maintenance during their week of reproductive endeavors. Metabolic compensation enables larval dobson flies to maintain preferred and fairly constant rates of R during winter (201-451 pl g-1 h~1; 5-15 C) and summer (985-1173 pl g- h1; 20-30 C); with a seasonal acclimatization change point between 15-20 C. Reduction of rates of R through undercompensation during the winter when food is scarce and through partial compensation at high temperatures during …

Using a micro-potometric method, it was ,found that X-irradiation (400 R - 18 Kr) of the shoots of the onion plant Allium cepa will produce an immediate, pronounced (200%) and reversible enhancement of the water uptake by the shielded roots. Unfiltered X-irradiation.(1200 R/min., 120 KVP, 5 ma) was delivered at right angles to the shoot. Readings were taken at 10-minute intervals before, and immediately following X-irradiation. The greatest enhancement occurred at dosages between 4.8 Kr (150%) and 6.0 Kr (190%). The data indicate that the irradiation effect on water uptake was a physical rather than a metabolic one.