The Sloe-Weevil 
result of my perfidy, they obstinately refused 
to bore any farther. The gummy barrier 
stopped them short; and it is not their habit 
to seek their freedom in another direction. 
Away from the bare floor, the bottom of 
the crater, they would infallibly come upon 
the pulp, which is no less detestable than the 
gum. In short, of the collection of larve 
subjected to my stratagems, not one has 
thriven; the sealing with gum has been fatal 
to them. 
This result puts an end to my hesitations: 
the cone set up in the centre of the pit is 
necessary to the existence of the grub seques- 
tered in the stone. Its tunnel is a ventila- 
ting-shaft. 
Each species certainly possesses its peculiar 
method of maintaining a connection with the 
outside world, when the larva lives under 
conditions in which the renewal of the air 
would be too difficult or even impossible if 
no precautions were taken. Generally, a 
fissure, a corridor, more or less unobstructed 
and the usual work of the grub, is enough 
to ventilate the dwelling. Sometimes it is 
the mother herself who sees to these hy- 
gienic requirements; and then the method 
223 
