WASPS, SOCIAL AND SOLITARY 



before continuing my walk to Pen-Chateau. I had seated 

 myself on the stones of a slope shaded from the sun and 

 was wiping the perspiration from my forehead, when I 

 saw a large wasp arrive directly before me. I instinctively 

 followed it with my eyes ; it paused some yards from the 

 mill on the side of the cliff, and began to open a nest 

 which was placed scarcely twenty inches from the foot of 

 a swallow-wort, a rather common plant in the neighbor- 

 hood of the ruin. She was Bembex rostrata at work at 

 provisioning her nest. 



Moved by curiosity, instead of going on to breakfast, I 

 awaited the exit from the nest, which took place in about 

 five minutes. Bembex scratched the sand and took flight 

 from the side of the cliff. How long would she be away ? 

 I looked at my watch and arose. 



Ought I to go or to wait a little while ? I took the latter 

 decision. Out of malice, and without any idea of trying a 

 control experiment to the admirable observations which 

 science owes to the naturalist of Se'rignan, of whom I was 

 not thinking at all, I cut close to the sand the stalk of the 

 swallow-wort and planted it a little nearer the mill, moving 

 it about two feet, and being careful to put in place of the 

 plant a little fragment of a bottle which I found in the mill. 

 I seated myself in the shade and waited. Twenty minutes 

 later the wasp dropped straight on to the place where I had 

 cut the plant, that is to say, it deviated from its nest by a 

 distance about equal to the displacement to which I had 

 subjected the swallow-wort. It walked right and left, agi- 

 tating its antennae, appearing confused as to the locality. 



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