FOSSORIAL HYMENOPTERA 
447 
dragging the caterpillar after her. But still the chamber was 
much too small, and the whole process had to be gone through 
again ; but not until six attempts had been made to fit the 
caterpillar in was the process completely satisfactory. 
On one occasion it had not been so carefully disposed at 
the edge as usual, and when Ammophila backed down the 
burrow she grasped the tail end instead of the customary 
place just behind the head, and it moved slightly. 
Ammophila at once perceived that something was wrong, 
hurried up from the burrow, examined the caterpillar care- 
fully, and rearranged it in the correct attitude ; so that, going 
down, she was able to catch hold of the neck, which custom 
seems to require. 
Here was a very imperfect worker, whose unskilfulness 
contrasts markedly with the nicety of method of another 
of the game species watched at a later date. 
She was seen carrying along a large Noctuid caterpillar, 
very many times heavier than herself : it was grasped by her 
mandibles a little distance behind the head, and the end 
of the slightly curved body projected a little between the 
second and third legs of one side of the Ammo'phila. This I 
have found to be the rule when a Sphegid carries a caterpillar. 
I followed her carefully, for some twenty yards altogether, 
marvelling how straight a course she kept through and round 
obstacles. When she came to a certain point, without any 
hesitation at all, she struck off at an angle to the right and 
preserved the fresh direction in a straight line for several 
yards until, at a little bare spot, she put down her burden, 
scratched away a little earth, lifted away a small piece of stone 
in her mandibles, and disclosed the mouth of the burrow. 
As usual, she went down head foremost to see that all was well 
in the chamber at the bottom, and then came up, seized the 
caterpillar which lay correctly at the mouth of the burrow, 
pulled it down after her, and then having safely bestowed 
it in the chamber and laid an egg on it, came out and filled 
up the burrow in the usual manner without any delay, and 
flew off. No hitch here ! The whole operation was carried 
out in a most workmanlike way, and as differently as possible 
from the bungling of the last one described. 
