466 - Trans. Acad. Sei. of St. Louis 
at the sight of the spiders that she threw away her mud 
and carried them all out. 
In Exp. XV, when a mother returned to her new cell 
and found I had filled it, flew up and repeatedly de- 
seribed circles of orientation before finally discarding 
her pellet of mud and carrying out the spiders. 
The last eight experiments were made expressly to 
test Fabre’s conclusions. One of these, Exp. 22, was the 
exact counterpart of his (the first spider was removed) 
and the others very similar (the first few spiders were 
removed), but not one of these eight wasps reacted as his 
individual did, and not one tended in the slightest degree 
to substantiate his sweeping statements that ‘‘the acci- 
dental difficulty which one insect is powerless to over- 
come, * * * any other, no matter what its genus or 
species, will be equally unable to overcome.”’ 
