Abstract
LONDON. Royal Society, November 25.—Sir J. J. Thomson, president, in the chair.—Prof. L. Hill: The growth of seedlings in wind. Mustard-and-cress seeds have been grown on lamp-wicks in a continuous wind of approximately 5 metres a second, and the control seeds in still air. The seeds grown in the wind are stunted and bent, and contain less water, more ash, less protein, and, presumably, more cellulose. To counterbalance the drying effect of the wind the seeds have been irrigated with water, and to balance the cooling effect of the wind due to evaporation this water has been warmed, so that a part of the irrigated wick in the wind has been as warm as, or warmer than, the control wick. By the combining effect of thorough wetting and warming the growth of the seeds in wind has been made much more nearly equal to that of the control. While the right amount of moisture is the most important factor, the cooling of the germinating seeds by the wind is also a factor in explaining the stunting of growth in wind-swept places.—Prof. P. T. Herring: The effect of thyroid-feeding and of thyroparathyroidectomy upon the pituitrin content of the posterior lobe of the pituitary, the cerebro-spinal fluid, and blood. (1) Neither thyroid-feeding nor thyroparathyroidectomy in cats affects the pituitrin load of the posterior lobe of the pituitary body as tested by the action of similar strengths of extract upon the rat's uterus and the blood-pressure of the pithed cat. (2) There is no evidence of the presence of pituitrin in the cerebro-spinal fluid of the fourth ventricle in normal, thyroid-fed, and thyroparathyroidectomised cats. (3) The defibrinated blood of normal, thyroid-fed, and thyroparathyroidectomised cats has no appreciable action on the rat's uterus. The blood of thyroid-fed cats has a greater depressor action upon the circulation of an anaesthetised cat than has the blood of the normal animal. The blood of thyroparathyroidectomised cfits has a pressor effect upon the circulation accompanied by contraction of the kidney and a diminution in the secretion of urine.—W. A. Jolly: Reflex times in the South African clawed frog. The reflex times of the homonymous and heteronymous reflexes in the hind limbs of the spinal clawed frog have been measured at temperatures ranging from 14° C. to 30° C. The average heteronymous time (66 observations) is 18.7 σ (0.0187 second). The average homonymous time (68 observations) is 14.9 σ. That is to say, the crossed reflex time is longer than the same-side reflex time by 3.8 σ.—Prof. J. A. Gunn and R. St. A. Heathcote: Cellular immunity. Observations on natural and acquired im-munitv to cobra venom. (a) Natural Immunity.—The minimum lethal dose of cobra venom for the cat is twenty times that for the rabbit (by subcutaneous injection per kg.), (b) Acquired Immunity. When a rabbit is immunised to cobra venom the isolated heart and intestine, perfused with Locke's solution so as to remove the serum, withstand higher concentrations of venom than the heart or intestine of a normal unimmunised rabbit.—L. T. Hogben: Studies on synapsis. III.: The nuclear organisation of the germ cells in Libellula depressa. (a) The nuclear organisation of the germ cells in Libellula depressa is investigated with a view to further knowledge of (i) relation of kinetic processes in premeiotic and meiotic phases, and (ii) bearing of nuclear emission in oocyte upon integrity of chromosome complex in meiotic phase, (b) In the premeiotic telophase the chromosomes spin out into finely granular loops, displaying initially a polar disposition, becoming increasingly more attenuated in the spirophase, and iiist recognisable individually in the prophase at attenuated convoluted filaments, (c) The Leptotene bouquet is regarded as owing its character to the polarisation of the normal telophase. (d) The behaviour of the “double nucleolus” has been thoroughly studied; the plasmosome is independent of the chromatin organisation of the nucleus.
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Societies and Academies. Nature 106, 488–491 (1920). https://doi.org/10.1038/106488a0
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DOI: https://doi.org/10.1038/106488a0