No abstract

No abstract

No abstract

WITH ONE FIGURE.The behavior of the pomace fly (Drosophila ampelophila) in respect to several kinds of stimulation has already been the subject of investigation. BARROWS ('07) has recently shown that the insect is positively chemotropic to certain strengths of odorous substances occurring in fermenting fruit, such as alcohol, acetic and lactic acids, and acetic ether. T o light varying in intensity from 5 to 250 candle powers Drosophila is positively phototropic; and under the influence of gravity it is negatively geotropic (CAR- P ENTER '05).In the present study of the reactions of Drosophila to stimuli other than those just mentioned, attention was first directed to the behavior of the insects when they pass from a region of optimum temperature into regions relatively warm or cold. The flies were confined in a flat glass box, 38 cm. long, 23 cm. wide, and 8 mm. deep. The edges of the box along the two sides and one end were sealed with aquarium cement and enamel, and thusmade water-tight. At the unsealed end of the box a small opening was left through which the flies could pass into the interior. All the movements of the insects could readily be observed through the glass, and the short distance that separated the roof and floor of the box permitted the use of a hand lens when desired.In the temperature experiments the box was partially immersed in water as shown in the accompanying sectional view of the apparatus.The water could be heated by means of an alcohol lamp placed beneath the vessel containing it, or it could be cooled by placing in the vessel small pieces of ice. By arranging the apparatus so

No abstract