138 Bulletin de la Société Royale Entomologique d'Egypte 
9. The Viability of the Offspring. 
1 have already pointed out in section VII that 
practically all the young hatch successfully from fer¬ 
tilized egg-cases while io % fail to do so from un¬ 
fertilized egg-cases. It must be remembered also that 
no young emerged from a large number of egg-cases 
laid by unfertilized females and that in the best cases 
not more than half the normal number did so. Bearing 
these facts in mind, we shall proceed to examine the 
viability of the young which succeeded in emerging 
normally so far as we could tell. 
We tried to bring up 71 of the young which 
hatched from three unfertilized egg-cases, of these 34 
died before the first moult and 22 during their later 
development, so that only i 5 reached the final stage. 
From the fertilized egg-cases, we tried to bring 
up 2 52 young, of these only 4 died before the first 
moult and 159 became adult. 
Of those which died after the first moult, a few 
were killed by ants, and most of the descendants of 
fertilized females which failed to reach the final stage 
were used as food for their older relatives in times of 
scarcity. As none of the descendants of unfertilized 
females were so used and only three were killed by 
ants, it is obvious that there is a far greater mortality 
among these not only before the first moult, but also 
during their later development. 
10. The Sex of the Progeny. 
We have already seen that 60 males and 63 females 
V 
