The Leaf-cutters 



of the cell and the upper surface towards the 

 outside. If alterations were necessary to re- 

 duce the lid to the diameter of the pot, the 

 disk would be bound to get turned over: the 

 piece, manipulated, set upright, turned round, 

 tried this way and that, would, when finally 

 laid in position, have its top or bottom sur- 

 face inside just as it happened to come. But 

 this is exactly what does not take place. 

 Therefore, as the order of stacking never 

 changes, the disks are cut, from the first clip 

 of the scissors, with their proper dimensions. 

 The Insect excels us in practical geometry. I 

 look upon the Leaf-cutter's pot and lid as an 

 addition to the many other marvels of instinct 

 that cannot be explained by mechanics; I sub- 

 mit it to the consideration of science; and I 

 pass on. 



The Silky Leaf-cutter {Megachile seri- 

 cans, FoN'SCOL. ; M. Diifoiirii, Lep.) makes 

 her nests in the disused galleries of the 

 Anthophora?. I know her to occupy another 

 dwelling which is more elegant and affords 

 a more roomy installation: I mean the old 

 dwelling of the fat Capricorn, the denizen of 

 the oaks. The metamorphosis is effected in 

 a spacious chamber lined with soft felt. 



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