Some observations on the physiological effects of gaseous ions

This paper reviews some of the evidence pertaining to the biological effects of gaseous ions. It appears to us that experimental data now available warrant the conclusion that reproducible biological effects occur in a variety of living forms including microorganisms, higher plants, insects, animals and man. The responses generally are limited in extent and to indict air ions as their sole cause requires great care in defining the experimental conditions. Some progress has been made in detecting the fundamental biochemical reactions associated with ion-induced physiological changes. The ready availability of excellent apparatus for generation and measurement of air-ions, coupled with present-day knowledge about their properties, makes critical experimentation possible.     

MORPHOLOGY OF SPORE DEVELOPMENT IN CLOSTRIDIUM PECTINOVORUM.

Fitz-James, Philip C. (University of Western Ontario, London, Ont., Canada). Morphology of spore development in Clostridium pectinovorum. J. Bacteriol. 84:104-114. 1962-The process of spore formation in Clostridium pectinovorum was followed by phase-contrast microscopy and by thin-section electron microscopy employing a polyester plastic for embedding. The development of the forespore membrane was found to be similar to that already described for the genus Bacillus, being, in addition, accompanied by considerable cell enlargement. The cortex, as in the bacilli, was found between the apposed layers of the double forespore membrane. The spore coat was laid down in the narrow zone of cytoplasm peripheral to the outer forespore membrane. As these layers formed, striking changes occurred in the fine structure of the spore nuclear material, mesosomes and ribosomes, reflecting the marked alterations in physical environment known to occur in a developing spore.     

The Effect of Hydrosatic Pressure Gradients on the Movement of Sodium and Calcium across the Root Cortex

The hydrostatic pressure gradient across the root cortex inducedby transpiration was simulated by raising the pressure on themedium surrounding the roots of detopped tomato (Lycopersicumesculentum) and castoroil plants (Ricinus communis).Applyinga pressure of 2 atm. resulted in a doubling of the sodium fluxfrom medium to xylern (table I). This flux depended on a maintainedsuply of Na in the medium (fig.1) indicating that there wasa small but readily available storage and exchange capacityfor Na in the root tissues. In the presence of metabolic inhaibitorsthe Na flux was considerablyu reduced and equalled the fluxof mannitol (talble II) believed to be a passive mass flow.The Na flux under a pressure gradient appeared therefore tobe metabollism-facilitated. Metabolic inhibition after the rootshad been allowed to take up Na led to a large flux of sodiuminto the xylem (Fig.2). This was considered to come from a largeunavailable store in the roots. Metabolism-facilitated processes also appeared to predominatein the flux of calcium to the xylem of Ricinus, buit not inthe flux through tomato roots. The location of the centripetal metabolism-facilitated transferand the available and unavailable stores is discussed in relationto the effects of pressure gradients.     

CYTOGENETIC ABNORMALITY IN MAN—Wider Implications of Theories of Sex Chromatin Origin

Female nuclei may be identified by means of sex chromatin. In general the number of sex chromatin bodies is one less than the number of X chromosomes. An exception to this rule is a case of sex chromatin-positive XO Turner''s syndrome. This case suggests the possibility of sex chromatin-positive XY males, and it may be evidence for chromosomal differentiation.     

Versuche zur Polyphosphat-Überkompensation in Hefezellen nach Phosphatverarmung

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