XVIII A PARASITE— THE COCOON 257 



a fault of construction. On the contrary it is a fresh 

 perfection. The insect would experience grave diffi- 

 culty in issuing from its strong box, so thick are the 

 walls, did not the line of junction, weaker than the 

 rest, apparently save much effort, as it is usually 

 along this line that the cover is detached when the 

 perfect Bembex emerges. 



I have called the cocoon a strong box. It is 

 indeed a solid article, both from its shape and the 

 nature of its materials. Landslips or falling sand 

 cannot alter its form, since the strongest pressure 

 of one's fingers cannot always crush it. Thus it 

 matters little to the larva if the ceiling of its burrow, 

 dug in loose soil, should sooner or later fall in, and 

 it need not fear, even should a passing foot press 

 down the thin covering of sand ; it runs no risks when 

 once enclosed in its stout shelter. Nor does damp 

 endanger it. I have immersed Bembex cocoons for a 

 fortnight in water without finding any trace of damp 

 inside them. Ah ! why cannot we have such water- 

 proof for our dwellings ? To sum up : the cocoon, 

 of graceful oval shape, appears rather the product of 

 patient art than the work of a grub. For any one 

 not behind the scenes, the cocoons which I saw in 

 process of construction with the sand from my 

 inkstand might well have been precious articles of 

 some unknown industry — great beads starred with 

 golden dots on a ground of lapis lazuli, destined for 

 the necklace of some Polynesian belle. 



S 



