350 Trans. Acad. Sct. of St. Louts 
of the clay had been bitten away from the periphery. 
By the next morning, more of the clay around the open- 
ing had been eut away, and inserting a stem of grass 
I sensed that some structural work had been done with- 
in. Late that afternoon I paused a moment just before 
train-time and removed the nest, incomplete as it was, 
to take home, and was surprised to see that more clay 
had been taken from about the aperture. Looking with- 
in, I could see at the far end a completed and open cell. 
Now to return to an examination of the first cell, 
whose closure I witnessed as recorded above. This 
mother had taken the unused cell and modified it in 
accordance with the plan illustrated in the diagram 
(fig. 39). In cell ‘‘A’’ the inside walls were smooth and 
slick, and a black spider of the species Phidippus tri- 
punctatus [J. H. Emerton] was within. Like many 
other individuals of this species observed, this wasp 
had failed to remove all of the legs of its prey, but those 
which she had taken off were amputated in a workman- 
like manner — that is, with a nice straight cut a few 
millimeters from the base. Again, she differed from 
others in her work in that the spider’s remaining legs 
were not completely paralyzed. How often we read in 
the text-books that the wasp stings the prey so that the 
body remains fresh food for the young, while the legs 
are paralyzed to protect the young from injury. In 
this spider the body seemed dead, but the remaining 
legs were active and clung to my pencil or finger with 
great tenacity. After the lapse of five days it was in 
about the same condition of activity as when the nest 
was first opened and 15 days later this spider shed its 
skin. This little incident may have a deeper meaning, 
too. It is possible that this species directs her stings 
to affect other parts besides the legs, for what would 
