REACTIONS TO LIGHT AND GRAVITY IN DROSOPHILA 79 
with these insects, a statement that does not hold at all for flies 
without wings. 
d. Removal of antennae 
The other type of operation which was attempted was the 
removal of the antennae. Inasmuch as these organs in Dro- 
sophila lie close against the head, considerable difficulty was ex- 
perienced in cutting them off. At length, however, a technique 
was developed which though tedious was successful in almost every 
case in removing the entire organ close up to the head. In this 
experiment four sets of tests were run which may be designated 
as A, B, C, and D. Since the method varied slightly in each of 
TABLE 13 
Controls without antennas removed 
LIGHT GRAVITY 
eau, Vertical Horizontal 
Male | Female 
Male |Female| Male |Female 
( 1 a0)! Sle) 27.0) 23.0 
SIAR Oto c rh barbs detrh hy = Sao wk 4 2 
[ 3 
Me Tacicci (ails eee eae ee 23° 23° 
Set B 1 100 | 97.5 20.0) 4820) 20:5) 35.0 
RG Rieke aaa wibst el a)ie\je| «| «| © \p ofc) e) oe (0.0 © = je wine “o 1 4] 5 48 | 0 99 0 27 } 5 
AVEO CT AUT OG iy apu aly cek ned ncest ce aieksesesye ers tonsa 23° 23° 
‘ ‘ f 1 50.5) 54.0) 33.0) 24.5 
Syenh (Chess oo eee Re ee are \ 9 
Memperature (GROUP a). ..0.- 2-2: 2B BB} 
1 36.6 olan 
Seta) AHMAR asen See srs k, { 9 99.7 ©10.5 
Teo ee 100 | 97.5 | 166.8| 135.5| 105.3| 82.5 
Pe cristae) 100 | 97.5 | 33.3] 44.5] 21.0] 27.5 
Merticalvexcesssammrallenarws 1 :pcth std Bases eo ain Hoos aay ee 12) 33 
Wertiealsexcess) shemallenee 6 5c .75..\<scbute eno clo acide ee eeneas 17.0 
