Antibacterial activity in the egg mass of a sea hare

Summary The eggs of a sea hare,Aplysia kurodai, contained antibacterial factors which probably play a role in the defense of eggs against bacterial infection. The active factors were composed of several heat-labile proteins, unrelated to lysozyme, and were produced in the albumen gland.     

Atomism, Poincaré and Planck

Planck's change in attitude to the question of whether atomic hypotheses were scientifically accessible, is discussed. It is argued contra Holton, that Planck's change in attitude to this question did not signal a methodological shift towards realism. The point of doing this is not just to investigate a significant episode in the history of quantum theory, but also to use the episode as a case study in support of a broader historical thesis. This thesis is that there was a widespread late-nineteenth century methodological tradition which motivated the change in status of certain ontological claims — e.g., that atoms exist — from ‘inaccessible to science’ to ‘scientifically acceptable’ even though those claims were not strictly ‘observable’. This methodological tradition is a hybrid of positivist and realist views. Thus, contrary to one popular view, the fin de siécle triumph of atomism is not to be seen as a triumph for a realist view of science Poincare's views are also used as an illustration.     

A potent attractant of zoospores ofAphanomyces cochlioides isolated from its host,Spinacia oleracea

A highly potent attractant of zoospores ofAphanomyces cochlioides, a causal fungus of the root rot disease of spinach (Spinacia oleracea), was isolated from spinach roots, and its structure was determined by spectroscopic evidence and chemical synthesis as cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone,1). A chromosorb particle prepared by soaking in solution of1 showed a potent attracting activity toward the zoospores using concentrations of1 above 10^–9 or 10^–10 M.     

Cynodontin,the tetrahydroxyanthraquinone ofCurvularia andDrechslera species

Summary The red anthraquinone derivative isolated from several Drechslera and Curvularia species has been identified as cynodontin (1,4,5,8-tetrahydroxy-2-methylanthraquinone), and not as 1,4,5,8-tetrahydroxy-2,6-dimethylanthraquinone as reported earlier. Both pigments showed similar physico-chemical properties. A good distinction could be obtained by gas-liquid chromatography.     

Physiological role of apyrene spermatozoa ofBombyx mori

Summary Observation by electron and phase-contrast microscopy demonstrated that inBombyx mori the dissociation of eupyrene bundles, apparently through digestion of the prostatic secretion or an endopeptidase, was promoted by the vigorously flagellating movement of apyrene spermatozoa in the spermatophore.