Chap. I. mSTIISrCT OF LOCALITY. 33 
neath their bodies issues in continuous streams. They 
are • solitary wasps, each female working on her own 
account. After making a gallery two or three inches 
in length in a slanting direction from the surface, the 
owner backs out and takes a few turns round the orifice 
apparently to see whether it is well made, but in 
reality, I believe, to take note of the locality, that she 
may find it again. This done, the busy workwoman flies 
aw^ay ; but returns, after an absence varying in different 
cases from a few minutes to an hour or more, with a 
fly in her grasp, with which she re-enters her mine. 
On again emerging, the entrance is carefully closed with 
sand. During this interval she has laid an egg on the 
body of the fly which she had previously benumbed 
with her sting, and which is to serve as food for the 
soft, footless grub soon to be hatched from the egg. 
From what I could make out, the Bembex makes a 
fresh excavation for every egg to be deposited ; at least 
in two or three of the galleries which I opened there 
was only one fly enclosed. 
I have said that the Bembex on leaving her mine 
took note of the locality : this seemed to be the expla- 
nation of the short delay previous to her taking flight ; 
on rising in the air also the insects generally flew round 
over the place before making straight off. Another 
nearly allied but much larger species, the Monedula 
signata, whose habits I observed on the banks of the 
Upper Amazons, sometimes excavates its mine solitarily 
on sand-banks recently laid baJe in the middle of the 
river, and closes the orifice before going in search of 
prey. In these cases the insect has to make a journey 
VOL. II. D 
