238 INSECTS. 



but I have observed this Bee more than once construct- 

 ing its burrow in the mortar of walls, and sometimes in 

 hard sandbanks. 0. aurulenta and 0. bicolor are Bees 

 which commonly burrow in banks ; the latter being very 

 abundant in some situations, forming colonies. But 

 although it appears to be the usual habit of these species 

 to construct tunnels in hard banks with great labour and 

 untiring perseverance, still we find them at times exhibit- 

 ing an amount of sagacity and a degree of knowledge 

 that at once dispels the idea of their actions being the 

 result of a mere blind instinct, impelling them in one 

 undeviating course. A moment's consideration will 

 suffice to call to mind many tunnels and tubes ready 

 formed, which would appear to be admirably adapted to 

 the purposes of the Bee. For instance, the straws of a 

 thatch, and many reeds ; and what could be more 

 admirably adapted to their requirements than the tubes 

 of many shells? So thinks the Bee. Osmia aurulenta 

 and 0. bicolor both select the shells of Helix hortensis 

 and Helix nemoralis : the shells of these snails are, of 

 course, very abundant, and lie half hidden beneath grass, 

 mosses, and plants ; the Bees, finding them in such 

 situations, dispense with their accustomed labours, and 

 take possession of the deserted shells. The number of 

 cells varies according to the length of the whorl of the 

 shell selected,, the usual number being four, but in some 

 instances they construct five or six, commencing at the 

 end of the whorl ; a suitable supply of honey and pollen 

 is collected, an egg deposited, and a partition formed of 

 abraded vegetable matter : the process is repeated 

 until the requisite number is formed, when the whole is 

 most carefully protected by closing up the entrance 

 with small pellets of clay, sticks, and pebbles ; these 



