76 7 ROBERT STANLEY McEWEN 
TABLE 13—Concluded 
With antennae removed 
LIGHT | GRAVITY 
peste | Vertical Horizontal 
Male | Female 
Male | Female} Male | Female 
il 91.0) 66.5 ORS 1.0 6.0 
St Aad SES Oe ies ees ety noe) ome 2 86:0) Sh25l> 10!) 6:0), 272510 1620 
{ 3 0 a0) 
Memperatures pase a. cay eee eo es Dae 99° 
BS) Cay Piles Ol Dr 
ieee SOs Neale Mae es aa ie | 92-9) (80:9) © 20a eta eo ae 
( 
MemMperatUreser 2k. s.ik tt eee eae oe 24° 24° 
; f 1 77.5) 100.0 Ol ieloe 1025) L230 
SICEAGe cb ean sah nase Bi asia 82 2 | 71.0] 90.1] 15.5] 16.5] 14.0] 13.0 
Temperature (Group b)....... 23° 23° 
1 | Also wings 6.0 13.5 
Sains Daan ste eR Oates 9 slipped 12.1 5 5 
Mem peravUnTe Mey eee ne et eee oe 23° 
Motaleseaccccee ate ae ae cee oe) 418 OA2 26! 42a O4RO ee ORO esha 
VAGV CLAD OS = rpS ayant eyeah ph cite een eer tn ee 83:6) 85:5) 1557) dids3) 15s5) Ae 
Wertieal excess! male an tcf ec os oon Re enh cee Seer ce OFZ 
Vertical excess) females saa ee a een eee 0.2 
these tests, each will have to be described separately. The re- 
sults, however, will be found summarized in table 13. 
In Set A, two groups of twenty flies were removed from the 
bottle shortly after hatching. One group was operated on at 
once, while the other was kept as a control. Five days later the 
group from which the antennae had been removed was tested 
for light reaction. Three hours later both groups were given a 
gravity test. In this case this test consisted of two series of five 
trials each. In the first series the tube was held vertically, and 
the index calculated as usual, the result being designated as the 
vertical index. The second series acted as a control, the tube 
