Abstract
CAMBRIDGE. Philosophical Society, November 22.—Prof. Seward, president, in the chair.—F. A. Potts: A note on vital staining. In studies which have been made on the penetration of neutral red into the living body of the soil nematode Diplogaster it is found that most of the stain makes its way through the mid-gut and none through the skin. In the mid-gut a zone of granules arranged peripherally round the lumen of the gut takes up the stain particularly.—W. F. Lanchester and A. G. Thacker: Preliminary note on the; superior vena cava of the cat. Thirty cats were dissected to observe the point of entrance of the internal jugular, which in every case except one fell into the external jugular. Observations were also made on the length of the superior vena cava in twenty-one adult cats, and the length appeared to be varying round more than one mean.—Miss M. D. Haviland: Preliminary note on a Cynipid hyperparasite of Aphides. Charips (Cynipidæ) is a hyper-parasite of Aphides through Aphidius (Braconidæ). The female pierces the Aphidius larva while the latter is lying inside the living Aphid, and deposits an egg within its body. The first-stage larva of the Cynipid is hypermetamorphic, with a thick chitinous skin and tail, but during development, which takes place within the Aphidius, the larva gradually assumes the form usual among parasitic Hymenoptera. Shortly before metamorphosis the hyperparasite leaves its host, the remains of which it devours, and its tracheal system becomes functional. It afterwards pupates within the cocoon previously woven by the Braconid.—Dr. E. H. Hankin and F. Handley Page: The problem of soaring flight (see p. 518).—Sir George Greenhill and Dr. G. T. Bennett: The rotation of a non-spinning gyrostat.—E. V. Appleton: A method of testing triode vacuum tubes. A dynamic method of measuring the slope of the principal voltage-current characteristic of a three-electrode thermionic tube is described.—W. B. Frankland: The astronomical bearing of the Einstein theory.—Dr. W. Burnside: The representation of the simple group of order 660 as a group of linear substitutions on five symbols. Except in the cases of two and of three variables, the explicit forms of groups of linear substitutions Have been given only in a few cases. Thus it is hoped that the explicit forms in the case referred to may be of interest. The existence of a cubic three-spread, in space of four dimensions, admitting a group of 660 collineations into itself may be compared with the more familiar case of Segre's cubic three-spread which admits a group of 720 such collineations.
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Societies and Academies. Nature 106, 520–523 (1920). https://doi.org/10.1038/106520a0
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DOI: https://doi.org/10.1038/106520a0