365 
G. S. Graham-Smith 
struggle. As soon however as the hold was relaxed the wounded specimen 
made attempts to get away. In this he was not successful for the first male 
again succeeded in getting on to his back, and after biting off a wing, buried 
his mandibles in his opponent’s back and bit savagely several times. After this 
the injured male made great efforts to get away and succeeded. Although he 
had been badly injured and died within a few hours, he seemed from his 
actions to be prepared to attack his adversary, if opportunity offered. The 
victor appeared to be much troubled by the fragments which found their 
way between his mouth parts, for even during the fight he often tried to 
remove them by passing his legs between his mandibles and subsequently 
rubbing them together. 
In many instances when several males were placed in a tube all except 
one were found dead and mutilated within a few hours. On one occasion when 
a puparium was opened two males were found within, one, though still able 
to stand, without his head. On another occasion a puparium on being opened 
contained 13 $, 13 female nymphs, and one large, active living male. The muti¬ 
lated remains of seven other males were also found. Only very rarely was 
more than one living male found in a puparium. 
Females. The females have large eyes and well developed wings, and can 
fly for a considerable distance. Liberated specimens were often seen to fly 
for some feet. Usually, however, they only fly for very short distances, one 
or more inches, in a jerky manner. Their movements are very rapid, unlike 
the slow movements of the males, and they are very frequently in motion. 
Much time is spent in cleaning their legs, wings, antennae and bodies, in the 
same manner and as thoroughly as flies. As previously stated they are apt 
to burrow through the corks of the tubes in which they are confined, whereas 
the males never attempt to do so. The females are ready to mate with the 
males very soon after emerging. 
Females, whether fertilised or unfertilised, confined with fly puparia in 
glass tubes live a long time. The longest periods noted were 95 and 79 days. 
The mean duration of life of 40 unfertilised females was 3G days and of 18 
fertilised females 33 days. These females seem to derive their nourishment 
from fluid exuding from puparia, which have been punctured by the ovi¬ 
positor of the parasite. 
Experiments with fertilised females. 
A number of experiments were carried out with females either derived from 
puparia containing males or kept in tubes with males. It was presumed that 
they had been fertilised. In most experiments a single such female was con¬ 
fined in a tube with one or more fly puparia. In some instances the puparia 
were removed after a few days to other tubes and the female given fresh 
puparia. In all cases the parasites which emerged were counted, and the 
puparium subsequently dissected to ascertain the number of males and living 
female nymphs still present in it. Even when no parasites emerged the puparia 
