458 Trans. Acad. Sci. of St. Louis 
spot two feet distant. Sometimes she would walk to- 
ward the nest, but always with the manner of one seek- 
ing for something lost. 
After three days the cell was still in the same condi- 
tion as I had left it; the wasp never finished it. I think 
that she firmly believed that her own nest was lost, and 
that the one which she visited again and again was the 
nest of another which had been filled with spiders. 
Exp. XIV. At 10:20 a new cell, the fifth on this nest, 
was begun, and in just one hour and a half the new 
compartment was completed and ready to be filled and 
sealed. At this point I came forward with unasked aid 
and placed therein fourteen spiders from another nest. 
The wasp returned with a load of mud, no doubt to put 
on the finishing ring, but when she saw the spiders she 
showed not the least surprise or concern, but proceeded 
to seal the cell with the pellet she had brought. Then 
she brought another and another and added them to the 
closing in the normal manner, showing almost human 
standards of conduct in being satisfied in doing the 
thing most convenient at hand which gives the appear- 
ance of work well done, and glad of the opportunity 
easily to forget that she had quite overlooked the prin- 
cipal duty of her life. She seemed to give no serious 
thought to the presence of the spiders, nor did she make 
an effort to compress them nor show any concern for 
depositing her egg. The sight or scent of the spiders 
seemed to afford sufficient stimulus to cause her to seal 
the cell. Perhaps the presence of mud already in her 
mandibles lent strength to the stimulus for this partic- 
ular action. 
At four o’clock that afternoon I found that this in- 
dustrious mother had made another cell and was finish- 
ing off what I thought must be the last ring. When she 
