The Mason-Wasps 



of two habitations: the cylinder, a novelty 

 unknown to its race; and the spiral stair- 

 case, the ancient ancestral home. 



The nests were finished at the end of 

 May and the Osmiae began to answer my 

 interrogatory. Some of them, the great ma- 

 jority, settled exclusively in the reeds; the 

 others remained faithful to the Snail-shell, 

 or else entrusted their eggs partly to the 

 spirals and partly to the cylinders. With 

 the first, who were the pioneers of cylindri- 

 cal architecture, there was no hesitation that 

 I could perceive : after exploring the stump 

 of reed for a time and recognizing it as 

 serviceable, the insect installs itself there 

 and, an expert from the first touch, without 

 apprenticeship, without groping, without 

 any tendencies bequeathed by the long prac- 

 tice of its predecessors, builds its straight 

 row of cells on a very different plan from 

 that demanded by the spiral cavity of the 

 shell, which increases in size as it goes on. 



The slow school of the ages, the gradual 

 acquisitions of the past, the legacies of 

 heredity count for nothing, therefore, in the 

 Osmia's education. Without any noviciate 

 on its own part or that of its forebears, the 

 insect is versed straight away in the calling 

 which it has to pursue; it possesses, in- 

 172 



