WASPS, SOCIAL AND SOLITARY 



sorrel. At such a time they seemed to have no mission 

 in life and no idea of duty. But when the air was clear 

 and bright and the mercury rose higher and higher, all 

 was changed. Their favorite working hours were from 

 eleven in the morning to three in the afternoon, and 

 when they did work they threw their whole souls into it. 

 It was well that it was so, for they certainly needed all 

 the enthusiasm and perseverance that they could muster 

 for such wearisome and disappointing labor. Hour after 

 hour was passed in search, and often there was nothing 

 to show at the end of it. Urnaria hunted on bare ground, 

 on the purslain, and most of all on the bean-plants. 

 These were examined carefully, the wasp going up and 

 down the stems and looking under every leaf ; but the 

 search was so frequently unsuccessful that in estimating 

 their work we are inclined to think that they can scarcely 

 average one caterpillar a day. 



In this species, as in every one that we have studied, 

 we have found a most interesting variation among the 

 different individuals, not only in methods, but in char- 

 acter and intellect. While one was beguiled from her 

 hunting by every sorrel blossom she passed, another 

 stuck to her work with indefatigable perseverance. While 

 one stung her caterpillar so carelessly and made her nest 

 in so shiftless a way that her young could survive only 



