Journal of experimental zoology . OF ABNORMAL 1 to 5 6 to 10 11 to 16 22 to 24 32 to 35 1370 608 260 • 46 44 644 29099 1713 589 209 40 4 2 44 77 50 8 9 633 286 90 12 11 recorded. When the eggs were transferred, they were not placeddirectly on the banana but upon a piece of filter paper placed overthe food. This was done to avoid covering the eggs with thefood, which may prevent them from hatching. The bottleswere then placed on ice. Some were kept there one to five days,others six to ten days, etc. The bottles were then removed toroom temperature. Tabl
Journal of experimental zoology . OF ABNORMAL 1 to 5 6 to 10 11 to 16 22 to 24 32 to 35 1370 608 260 • 46 44 644 29099 1713 589 209 40 4 2 44 77 50 8 9 633 286 90 12 11 recorded. When the eggs were transferred, they were not placeddirectly on the banana but upon a piece of filter paper placed overthe food. This was done to avoid covering the eggs with thefood, which may prevent them from hatching. The bottleswere then placed on ice. Some were kept there one to five days,others six to ten days, etc. The bottles were then removed toroom temperature. Table 9 and diagram 3 give the of the flies which hatched had lost one or more legs andtherefore could not be classed as abnonnal or normal. For thisreason the number hatched is larger than the sum of abnormaland normal. The per cent of abnormal flies varied directly with the lengthof exposure to cold, but the number hatched varied inverselywith the length of exposure to cold. As many of those which did MILDRED A, HOGE. 15 20 25 Days left on ice Diagram 3 not hatch would have been abnonnal, the percentage of abnormalflies would probably have been larger, had the full numberhatched. These two experunents show conclusively that a temperatureof 10°C. ±, maintained throughout development, produces a largepercentage of abnormal flies. LOW TEMPERATURE WITHOUT EFFECT OX WILD STOCKS Fhes from a wild stock were mated, both in pairs and in massculture and placed in the ice box immediatelj or several daysafter mating. The larvae were removed before they the 1352 flies which hatched, only one showed any abnonnal-ity. The test was repeated, and this time the eggs were cooledshortly after they were laid, and the pupae were allowed tohatch in the ice box. The 214 flies which hatched were allnormal. Low temperature, therefore, does not cause redupli-cation in nonnal stock. The one abnormal fly that appearedin the first case was probably due to infection. Possibly it may
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectzoology, bookyear1904
