. Contributions from the Hull Botanical Laboratory. Plants. Fig. 2.—a, result of treat- ing a bud, just beginning to show the petals, for three days with 1 part of illuminating gas in 20,000; b, result of the treat- ment of a similar bud, for the same length of time, with 1 part of ethylene in 500,000. showed a slight growth of the petals, but never opened. Later they shriveled and turned yellow. Our experiments in which individual buds were enclosed and exposed to illu- minating gas began with liter flasks in which as much as 25cc of gas was used. The time of exposure was usually three days,
. Contributions from the Hull Botanical Laboratory. Plants. Fig. 2.—a, result of treat- ing a bud, just beginning to show the petals, for three days with 1 part of illuminating gas in 20,000; b, result of the treat- ment of a similar bud, for the same length of time, with 1 part of ethylene in 500,000. showed a slight growth of the petals, but never opened. Later they shriveled and turned yellow. Our experiments in which individual buds were enclosed and exposed to illu- minating gas began with liter flasks in which as much as 25cc of gas was used. The time of exposure was usually three days, starting when the petals were just beginning to show. A gradual reduction of the concentration by reducing the amount of gas used and by increasing the size of the enclosure finally located the toxic limit. The highest concentra- tion did no apparent injury to the vege- tation; but the effect upon the buds was made apparent by a failure to open, by a discoloration and withering of the petals, and by the projection of the stigmas. When using icc of illuminating gas to 20,000", the stigmas still project as shown in fig. 2, a; of illuminating gas did not suffi- ciently retard the growth of the petals to cause projection of the stigmas, yet the buds never opened farther than shown in fig. 3, although the petals remained fresh for several days. Very young buds were also exposed to the last con- centration of the gas (1 part in 40,000, or per cent.) for a period of three days. The injury was not apparent at first, and the buds remained green for several days, but finally turned brown and withered. A series of exposures was also made on the open flowers. We selected for this work those that had just opened, in order to be sure that any change produced was due to the toxicity of the gas rather than to the natural death of the flower. treating3a_bud,Ujust Here as well as in all the other experiments checks beginning to show were kept. Fig. 4, a shows a flower before
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1895
