The Resin-bees 



the Resin-bce persists in using big Snail-shells 

 just as though her ancestors had never known 

 the dangers of the Osmia-blocked vestibule. 

 Once these facts are duly recognized, the con- 

 clusion is irresistible: it is obvious that, as the 

 insect does not hand down the casual modifi- 

 cation tending towards the avoidance of what 

 is to its disadvantage, neither does it hand 

 down the modification leading to the adoption 

 of what is to its advantage. However lively 

 the impression made upon the mother, the ac- 

 cidental leaves no trace in the offspring. 

 Chance plays no part in the genesis of the 

 instincts. 



Next to these tenants of the Snail-shells we 

 have two other Resin-bees who never visit the 

 shells to seek a refuge for their nests. They 

 are Anthid'iiim qiiadrilobum, Lep., and A. 

 LatrcilUi, Li:P., both exceedingly uncommon 

 in my district. If we meet them very rarely, 

 however, this may well be due to the diffi- 

 culty of seeing them; for they lead extremely 

 solitary and wary lives. A warm nook 

 under some stone or other; the deserted 

 streets of an Ant-hill in a sun-baked bank; 

 a Beetle's vacant burrow a few inches below 

 the ground; in short, a cavity of some sort, 



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