84 ROBERT STANLEY McEWEN 
In both Groups A and B one fly was lost before the re-test. Table 
17 shows the results. 
For the sake of comparison the average indices for light and 
gravity obtained from the above experiments on wild, vestigial, 
TABLE 17 
Temperature 24° 
BEFORE WING REMOVAL AFTER WING REMOVAL 
TESTS Li Gravity Tosa | Gravity 
aight (vertical) ght (vertical) 
Male | Female| Male | Female} Male | Female} Male | Female 
= f 1 83.3) 34.1] 86.6) 40.0 
GroupsAy Ane: f 9 55.5 83.3 
i {| 1 | 88.3] 51.6] 80.8] 45.0 
Groupebige seers t 9 69.4] 74.0 
A) (2 eases] * 48:3) sie) Mao 1 
Groupe Cen ere p 9 83.3 85 0 
say Ea 325.7| 134.0| 334.0] 134.1] 124.9 157 Git) ae 
Averages......... 81.4; 44.6) 838.5} 44.7] 62.4 78.6 
strap and curled flies have been brought together in table 18. 
From this table it is evident that there is a steady drop in pho- 
totropic response which in a rough way is directly proportional 
to the lack of development of the wings. 
The curious effect of defective wings upon light reaction as in- 
dicated by the above experiments made it desirable to examine 
TABLE 18 
Temperature 23°-24° 
BEFORE WING REMOVAL AFTER WING REMOVAL 
ENP REU NETS) OH Light Gravity Light Gravity 
Male | Female} Male | Female} Male | Female} Male | Female 
Wild acte ens tare eee ete OS O97. 22 OURS m| MOOR OM||rolesele omen mee m AOR 
Curledasees: See eon ee 81.4 | 44.6 | 88.5 | 44.7 | 62.4 78.6 
Straps Lee? epee eee Rod || AOS || ev |) sk)sG) |) toss} 68.4 
Westigial tsa pee ace | lace Oe Soe ane GAG ; 
