One of the few processes of an avian population that presents the opportunity to collect sensitive information about the performance of that population is growth rates of young throughout the brooding period. Growth rate data are sensitive to many conditions of the breeding cycle: proximate influences, such as food availability and weather (Fran-cis, et al., in prep.), and ultimate factors, suc...

s Seventh International Congress of Biochemistry, 1967, p. 230. 13. NEILANDS, J. B., AND TUPPY, H., Biochim. Biophys. Acta, 38, 351 (1960). 14. SHEMIN, D., in S. P. COLOWICK AND N. 0. KAPLAN (Editors), Methods in enzymology, Vol. 4, Academic Press, New York,

I N recent years substantial information has been gained concerning the size and topology of DNA (deoxyribonucleic acid) molecules of viruses (for reviews see VINOGRAD and LEBOWITZ 1966; COHEN 1967; THOMAS and MACHATTIE 1967) , bacterial plasmic and sex factor (ROTH and HELINSKI 1967; HICKSON, ROTH and HELINSKI 1967), Mycciplasma hominis (BODE and MOROWITZ 1967), bacteria (CAIRNS 1963) and mito...

(Mikkelsen 1967) -3% (BrƒÓgger 1967); in patients born to mothers younger than 30 years it is 8.3%, and in those born to mothers older than 30 years it is 1.2% (Mikkelsen 1967). Between the patients born to mothers older and younger than 30 years the difference is highly statistically significant. The frequency of D/G translocations is about the same as the frequence of G/G translocations. Abou...

Several studies have been reported on the cytogenetic analysis of spontaneous abortions (Aspillage et al., 1966; Boue, Boue, and Lazar, 1967; Carr, 1967; Clendenin and Benirschke, 1963; Hall and Kallen, 1964; Inhorn, Therman, and Patau, 1964; Rashad and Kerr, 1965; Singh, Rubinoff, and Carr, 1966; Szulman, 1965; Thiede and Salm, 1964; Thiede and Metcalfe, 1966; Waxman, Arakaki, and Smith, 1967)...

Gully erosion is one of the most complicated and destructive forms of water erosion. In order to prevent this erosion, the important factors advancing gully head must be recognized. Nowadays, several models have been proposed in measuring gully head advancement and identifying the severity of erosion. These models must be calibrated for each country to see whether they are applicable or not. So...

Atopic abundances and the reso lu t ion of small t ime differ­ ences in the formation of p lane ta ry objects, Earth Planet. Sci Lett., 5, 3 6 1 3 7 6 , 1 9 6 9 . fmn R ®-> Heavy rare gases in silicates f rom t h e Esterville lesosiderite,X Geophys. Res., 71, 2 8 1 5 2 8 2 9 , 1966 . toin R. 0 . , Trapped neon in meteor i t e s , Earth Planet. Sci ' letl 1 1 3 1 8 , 1967 . Pepin R 0 . , and P. ...

Recent studies of the fluxes of sodium and chloride across euryhaline teleost fish have shown that acclimation to fresh water involves a sharp reduction in the flux of both ions (Evans, 1967 c, 1969; Motais, 1967; Maetz et al. 1967 a, b; Potts & Evans, 1967; Ports et al. 1967). It has been shown, at least in Fundulus heteroclitus (Potts & Evans, 1967), Tilapia mossambica (Potts et al. 1967), Xi...