BEHAVIOR. i 
around toward her. He sometimes goes to the other side, but usually 
circles rapidly to the rear. No wing-motion by the male has been 
seen when he was in any position but the above. When he circles to 
the rear, the female may spread her wings as in D. funebris. The male 
then rushes in and copulates. One pair in copula 2 minutes. 
Drosophila obscura: Vibration (both wings at once), scissors move- 
ment, circling, male genitalia go up underneath. The female does 
not spread her wings. In copula 4, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 11 
minutes. 
Drosophila repleta: Scissors movement, licking; no vibration or 
circling. The female spreads her wings as in D. funebris, but not so 
widely. After the genitalia become separated the male remains in 
position for about 30 seconds. One pair copulated twice within 10 
minutes. In copula 2, 3 minutes. 
Drosophila robusta: Scissors movement, waving, licking; no vibra- 
tion or circling. The female does not spread her wings before the male 
mounts. In copula 2 minutes. 
Drosophila simulans: Vibration, scissors movement, circling, licking, 
male genitalia go up underneath, female does not spread her wings— 
all as in D. melanogaster. In copula 19, 20, 23, 25, 25, 32, 32, 36, 
48 minutes. 
Drosophila transversa: Scissors movement, rapid waving, circling, 
licking. No vibration seen. Copulation itself not observed. (These 
notes possibly refer to D. putrida.) 
Drosophila virilis: Scissors movement, waving, licking; no vibration 
or circling. The female spreads her wings before the male mounts. 
If he fails to mount she keeps them apart a few seconds. The male 
genitalia go up underneath. Mounting is done slowly. In copula 
2, 3, 4, 4, 4, 5 minutes. 
Drosophila willistoni: Scissors movement, licking; no circling or 
vibration seen. In copula 27 minutes. 
Drosophila hypocausta Osten Sacken: De Meijere (1914. Tijds. v. 
Entom., 54) has given notes from Jacobson showing that courtship in 
this oriental species is accompanied by circling and licking. 
Scaptomyza adusta: Very little courtship, all done from behind the 
female. Occasional scissors movement, slight vibration, not much 
licking, no circling. Male rushes at female and doubles his abdomen 
wp underneath; usually fails to mate. The female does not spread 
her wings. Mounting does not occur until the genitalia are connected. 
The final position is the same as in most species of Drosophila. In 
copula 8 minutes. 
Scaptomyza graminum: Same as S. adusta. In copula 3 minutes. 
Chymomyza amena: None of the characteristic acts of courtship in 
Drosophila seem to occur in this genus, except that a modified waving 
is constantly being done by both sexes even when not sexually excited. 
