. Radium, X rays and the living cell. maranthus wereobserved in a series of experiments by Congdon, who exposedthem to the beta and gamma rays from 8 mgs. of radium. Hefound that these seeds were affected to varying extents when theywere all exposed to the same quantity of irradiation. He was not,however, able to trace any relation between the sensitiveness tothe rays and the chemical constitution of the seeds. SEEDS, PLANTS, ETC. 137 Falta and Schwartz exposed oats under growing conditions toradium emanation, and found that their growth was apparentlyaccelerated, as may be seen from the follo
. Radium, X rays and the living cell. maranthus wereobserved in a series of experiments by Congdon, who exposedthem to the beta and gamma rays from 8 mgs. of radium. Hefound that these seeds were affected to varying extents when theywere all exposed to the same quantity of irradiation. He was not,however, able to trace any relation between the sensitiveness tothe rays and the chemical constitution of the seeds. SEEDS, PLANTS, ETC. 137 Falta and Schwartz exposed oats under growing conditions toradium emanation, and found that their growth was apparentlyaccelerated, as may be seen from the following data : (i) Concentration of emanation .0124 milli-curie per litre ;after nine days : In emanation vessel 45 shoots measured 18-19 cms. long. ^-11 -16 21 In control vessel - 20 ,, ,, 15- - 28 ,, ,, 2-10 (2) Concentration of emanation .09 milli-curie per litre ; afterseven days : In emanation vessel 96 shoots, total length 14 metres. In control vessel - 94 ,, ,, 8 They state that the shoots were rich in chlorophyll, and in this if. 48 HOURS 24 HOURS I HOUR CONTROL Fig. 19.—hyringa Vulgaris exposed to mgs. radiiim chloride. connection the experiments of Hebert and Kling {vide infra)upon lilac leaves are interesting, as showing that the chlorophyll-containing cell can exercise the power of assimilation when underthe influence of nearly one hundred times the concentration ofemanation used in the above experiments. Some of the most important experiments upon plant life inthis connection have been made by Molisch, who has shown that 138 SEEDS, PLANTS, ETC. if certain buds are suitably irradiated, then growth will befavoured or hindered thereby according as the buds are in theresting or growing stage respectively. WTien buds of Syringa vulgaris were irradiated in the restingstage by beta rays, or when exposed to the emanation, the openbuds appeared sooner than in the control experiments. Theperiod at which the buds are irradiated is important, as thefollowing series will sh
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