The Mason-bees 



of some square yards. Its recollections, if it 

 have any, serve it badly; the outward appear- 

 ance gives it no information; and its drill en- 

 ters wherever it may happen to discover a 

 cell, at points that have already perhaps been 

 pierced several times over. 



It may also happen — and this appears to 

 me the most frequent case — that one exploiter 

 of a cell is succeeded by a second, a third, a 

 fourth and others still, all fired with the new- 

 comer's zeal because their predecessors have 

 left no trace of their passage. In one way 

 or another, the same cell is exposed to mani- 

 fold layings, though its contents, the Chali- 

 codoma-grub, be only the bare ration of a 

 single Leucospis-grub. 



These reiterated borings are not at all rare : 

 I noted a score of them on my tiles; and, in 

 the case of some cells, the operation was re- 

 peated before my eyes as often as four times. 

 Nothing tells us that this number was not 

 exceeded in my absence. The little that I ob- 

 served prevents me from fixing any limit. 

 And now a momentous question arises : is the 

 egg really laid each time that the probe enters 

 a cell? I can see not the slightest excuse for 

 supposing the contrary. The ovipositor, be- 

 300 



