THE LIFE OF A SOLITARY WASP 215 
wasp has a wonderful knowledge of the anatomy of 
caterpillars! “It is,” writes Fabre, “in this triple blow 
that the infallibility, the infused science, of instinct, 
appear in all their magnificence.” 
These words are in the main true, but more recent 
investigations have shown that instinct is, in this case, 
not absolutely infallible. The wasp does sometimes 
make a “boss shot.” It occasionally happens that a 
stab fails to reach the nerve ganglion. When the wasp 
has stored the cell with eight caterpillars she closes 
it by roofing it with mud. I believe that eight is the 
number of caterpillars she allows to each egg, but there 
again I speak not with certainty. 
These observations were made at random and were 
often interrupted. After the cell had been closed there 
was still plenty of room left in the hole in the bed- 
post ; in this space the wasp laid another egg, killed 
more caterpillars, and then closed the cell with mud, 
making the top of the roof flush with the summit of 
the post. She then proceeded to stock the hole in the 
bed-post, behaving in precisely the same way as before. 
Having completed the second nest, she forthwith began 
to line the third hole with mud, and was stocking it 
with caterpillars, when I cut short her life. I had to 
sacrifice her in the interests of science, in order to find 
out the species to which she belonged. 
Five days after she had closed the first nest I opened 
it, and found that all the caterpillars had disappeared, 
and that a great fat white grub, fully an inch in length, 
had taken their place. This had emerged from the 
egg, and then devoured all the caterpillars. The length 
