Abstract
LONDON. Royal Society, May 14.—Sir William Crookes, president, in the chair.—Dr. A. D. Waller: The various inclinations of the electrical axis of the human heart. Part IA.—The normal heart.—Effects of respiration. Continuation of previous observations (Phil. Trans., 1889, p. 169) in which the electrical effects of the human heart were first demonstrated, and the distinction made between favourable and unfavourable leads dependent upon the obliquity of the cardiac axis, and of subsequent observations (Proc. R.S., B, vol. lxxxvi., p. 507, 1913) to determine the angular value of the inclination of the electrical axis.—Dr. D. H. Scott and Prof. E. C. Jeffrey: Fossil plants showing structure from the base of the Waverley Shale of Kentucky. The specimens were collected by Prof. C. R. Eastman and Mr. Moritz Fischer, near Junction City, Boyle County, Kentucky. The nodule layer containing the plants is described by Prof. Eastman as lying at the base of the Waverley (Lower Carboniferous) and immediately above the Genessee Black Shale of Upper Devonian age. The anatomical structure is, on the whole, well preserved.—F. Kidd: The controlling influence of carbon dioxide in the maturation, dormancy, and germination of seeds. Part ii. The inhibitory effect of carbon dioxide on the germination of seeds previously described is dealt with in relation to temperature and oxygen supply. In relation to temperature the result obtained is unusual, the inhibitory action being more pronounced at low temperatures than at high. At 3° C. complete inhibition was obtained with 4 per cent. CO2; at 17° C. as much as 24° C. had to be employed to obtain the same result. Varying partial pressures of oxygen also effect the inhibitory action of carbon dioxide, but to a less degree than temperature. Thus with 5 per cent, oxygen, 15 per cent. CO2 produced inhibition; with 20 per cent, oxygen, 27 per cent. CO2 was necessary. The author emphasises the fact that the adjustments of the moist seed by which it is enabled to continue dormant in the presence of oxygen and water, rather than those of the dry seed, are likely to have formed the central problem of seed life in nature. A low temperature and a decreased oxygen supply are often the natural conditions of a seed's environment in the soil. Correlating the results obtained in this and in a former paper, the author strongly emphasises the controlling influence of carbon dioxide in the biology of seeds. It appears that the normal resting stage of a seed is primarilv a phase of narcosis.—D. Thomson and J. G. Thomson: The cultivation of human tumour tissue in vitro. Small portions of tissue from two human tumours, (a) intracystic papilloma of the ovary, and (b) carcinomatous lymphatic gland, have been cultivated successfully in a medium composed of fowl blood plasma + extract of embryonic chick. This proves that human tissue can be grown in in vitro a medium obtained entirely from a bird. This is contrary to what was previously believed, since it was considered that the tissue of a certain animal could only grow in a medium composed of the blood plasma of the same species of animal.—H. G. Thornton and G. Smith: The nutritive conditions determining the growth of certain fresh-water and soil protista. Experiments made on the growth of Euglena viridis in artificial media showed that, in addition to those inorganic constituents necessary for the growth of a green plant, which were supplied by Miguel's formula for growing diatoms, a certain quantity of organic material, e.g. infusion of hay, was necessary. In order to determine the constituent in this organic material which stimulated growth, various pure substances, such as carbohydrates, tartaric acid, saccharin, allantoin, peptone, and various amido-acids, were used in dilute solutions. Of these, only very weak solutions of amido-acids favoured a really strong growth, the most favourable substances being tyrosin and phenyl-alanine, which are very slightly soluble in water. Experiments with soil flagellates, especially Prowazekia terricola (Martin), showed that they could be cultivated in many solutions in which bacteria flourished, the flagellates feeding on several different kinds of bacteria. Samples of various types of soil and water were tested for the presence of bacterial-feeding flagellates, and these were found in all the samples, being most abundant in highly manured soil. The wide distribution and abundance of these soil flagellates, and their very rapid growth in the presence of bacteria, suggests that they are of importance in the economy of the soil.
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Societies and Academies . Nature 93, 313–315 (1914). https://doi.org/10.1038/093313a0
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DOI: https://doi.org/10.1038/093313a0