The Mason-Wasps 



the caterpillars stabbed by the Ammophilae; 

 I believe rather that the position is natural 

 to the grub during inaction, even as it is 

 natural for the luli ^ to coil themselves into 

 a spiral. In this living bracelet there is a 

 tendency to return to the rectilinear conform- 

 ation; it is a bent bow fighting against the 

 obstacle that surrounds it. By the very 

 fact, therefore, of being curled up, each 

 grub keeps more or less steady by pressing 

 its back a little against the wall; and it re- 

 tains its place even when the cell approaches 

 the vertical. 



Moreover, the shape of the cell has been 

 calculated with a view to this manner of 

 storing. In the part next the entrance, the 

 part which one might call the store-room, 

 the cell is cylindrical and narrow, so as to 

 afford the living rings as little space as pos- 

 sible; they are thus kept in position and are 

 unable to slip. It is here that the grubs are 

 stacked, squeezed one against the other. 

 At the other end, near the back, the cell 

 expands into an ovoid to give the larva 

 elbow-room. The differences between the 

 two diameters is very perceptible. At the 

 entrance I find only four millimetres : ^ at 



* The lulus belongs to the Myriapod family, which in- 

 cludes the Centipedes, etc. — Translator's Note. 

 2 .156 inch. — Translator's Note. 

 54 



