June] The Nesting Habits of the Pulp-Making Bee 105 
happened; when I again looked, she had bitten away so much 
pith at the left side, in her apparent attempt to loosen the un- 
yielding plug, that she had opened a passageway around the 
side of it, through which she had escaped. This had led her 
directly into the bottom end of the empty cocoon above her 
and she accepted this as a passageway quite unhesitatingly. 
The channel had originally been only l/ 8 inch in diameter, but 
she had dug out the pith at one side until at that point it was 
more than l/4 inch. After this unusual exertion she relaxed for 
a few minutes of rest; she certainly looked very much at home 
as she lay there in the cocoon which fitted her perfectly — a 
replica of the one she had so recently left. 
Eternal vigilance is the price of scientific data; had I not 
returned at that moment I should never have known her method. 
I expected that next she would go right on through the roof, but 
for twenty minutes she carefully cleaned out this cell, and 
with some difficulty pulled away the last bits of cocoon that 
adhered to the walls. There was no apparent need for this, ex- 
cept as a preliminary to attacking the wall to loosen the top 
plug. The old plug bottom that, she had just passed still 
adhered to the walls and while her body now pushed it downward 
she made no further attempt to remove it ; it was no longer in 
her way, so she went on directing her energy to the top plug 
and the pith on the left side near it. Her process of alternately 
biting and scratching out the pith, and belaboring the plug, was 
repeated, accompanied by the same rasping noises and occasion- 
ally the falling of bits loosened from the plug, showing that her 
efforts were not entirely for naught. Of course all this was 
making it easy for the fourth and last to emerge. Since No. 
3 was doing the pioneer work that normally would fall to no. 1 
and no. 2, and was succeeding manfully, it again brings to our 
attention the point that the first-born is not especially endowed 
with the ability to do worthy work, but it is all a matter of 
native intelligence, perseverance and strength. If this biting 
the way out is instinctive — chain instinct if you please — I won- 
der what happens to those which have no opportunity to use 
it, — those which merely follow the pioneers and have egress 
