The Mason-Wasps 



tive insect. So as not to influence each 

 other in our appreciation of facts which, by 

 their rapidity, might leave room for doubt, 

 we each agreed to keep our results secret 

 until we were both certain of our data. 



Fully instructed as to what to do, Claire 

 begins. She soon discovers on the banks 

 of the Aygues some poplars covered with 

 Chrysomela-larvae. From time to time an 

 Odynerus arrives, alights upon a leaf and 

 goes off again with her capture in her legs. 

 But things are happening too high up ; de- 

 tailed inspection of the struggle between the 

 huntress and the victim is impracticable. 

 Moreover, the appearances of the Ody- 

 nerus on the tree which was being watched 

 among so many others, all equally pro- 

 pitious to the chase, occur at long intervals, 

 which try the patience beyond all bounds. 

 Tenacious in her desire to see, to learn and 

 to be useful to me, my zealous collaborator 

 bethinks herself of an ingenious expedient. 

 A young poplar, with a wealth of Chryso- 

 melae, is pulled up, together with the lump 

 of earth clinging to it. Lavish precautions 

 are taken to avoid the shocks which, du- 

 ring the uprooting and the removal, might 

 cause the herd of larvae to drop off. The 

 business is so successfully done that the tree 

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