194 NEUROPTERA. 
Mother, First it marks a circle, of the 
size intended for the outer rim ; then, 
moving round in this circle, it loads its 
flat head with sand, by means of the 
fore foot that is next the centre, and ex- 
pertly jerks the sand over the outside 
of the rim. When one foot is tired it 
makes use of the other for its shovel ; 
but in order to form the pit into the 
shape of a funnel, it is obvious that the 
sand must be always removed from the 
inside of the ring in which the animal 
works : it is for this reason that the foot 
nearest the centre is employed; and there- 
fore in changing feet it is necessary to 
move round in the contrary direction. 
The regularity, however, of the operation 
is not interrupted by this change of tools. 
One ring, or trench, is first completed ; 
the next is made by reversing the course 
of the former ; and thus trench after 
trench, in alternate directions, is thrown 
out till the whole task is finished. 
Lucy, How curious it must be to 
