. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. o: g LLJ 8 jg i FIGURE 2. Hatching of Daphnia embryos when given a single 16-hour light period or two pulses of light that form the skeleton of one 16-hour light period. The embryos were first exposed at 0900 EST after having been in constant darkness and near an open (September) window for 17 or 31 days. Prior to that time the embryos were in constant darkness and temperature (19° C) for four months. (See text for additional details.) of the second exposure was critical. Wh
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. o: g LLJ 8 jg i FIGURE 2. Hatching of Daphnia embryos when given a single 16-hour light period or two pulses of light that form the skeleton of one 16-hour light period. The embryos were first exposed at 0900 EST after having been in constant darkness and near an open (September) window for 17 or 31 days. Prior to that time the embryos were in constant darkness and temperature (19° C) for four months. (See text for additional details.) of the second exposure was critical. When exposed to a second pulse from hours 14 to 16 following the start of the first pulse, activation ( per cent), as measured by hatching, was equivalent to a continuous 16-hour light exposure ( per cent). A second exposure from hours 10 to 12 was not effective ( per cent hatch) as was a single exposure given from hours 14 to 16. Exposure to one 14-hour skeleton resulted in the hatching of i () the number activated by one 16-hour skeleton. This result suggested that the critical photoperiod for the embryos was approximately 14 hours of light. Further de- ductive support for 14 hours as the critical daylength was given by the number. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
