Séance du 16 Avril W24 
133 
will emerge even in January and February which 
are the coldest months. It is therefore not surprising 
that his observations and ours should not agree and 
it is interesting to note that the less favourable cli¬ 
matic conditions in France bring. about the same 
result as virginity in Egypt, although by an entirely 
different process. 
In the following paragraph, Fabre states (that 
hatching, though still incomplete, may occasionally 
take place throughout the egg-case at the same time 
and suggests that some disturbance is propagated 
from egg to egg causing the simultaneous hatching 
of many young. This suggestion is quite in accord 
with our observations, if the eggs which fail to hatch 
also fail to carry the hatching impulse to their 
neighbours. For in such a case a barrier of ‘dead’ eggs 
would separate the egg-case into two parts each of which 
would require an impulse within itself to start. 
It sometimes happens that an emerging Mantis 
reaches the surface of the egg-case and then fails to 
free itself from what, for want of a better name, I 
shall call the ‘hatching sheath.’ This is very rare 
in the case of fertilized egg-cases. From the ioi egg- 
cases referred to above 5713 young emerged and there 
were in addition only 9 larvae which failed to free 
themselves 
In the case of unfertilized females these may be as 
much as 20 % of the total number, and in the whole 
of this generation amounted to 371 as against 3 i 36 
which liberated themselves completely, that is 10.6% 
of the total. 
As the inclusion of these failures would make 
no difference to the conclusions drawn previously, I 
