THE OSMI^. 247 



bee in order to obtain her rights, and the new comer was quite 

 ready for the combat. An Osmia which Hves in Algiers has the 

 wit to choose snail shells for its nest, and forms cells within 

 them with a mixture of earth and cow-dung. Another well- 

 known insect {Osmia aiirulenta) seeks for the dried twigs of 

 brambles, clears them out, and constructs cells inside, one after 

 the other, with a small quantity of mortar. Its work is com- 

 paratively easy and simple, especially when compared with the 

 labours of the Chalicodoma and other Apidcs. 



In the engraving the perfect insects are seen in flight, and one 

 is crawling upon a leaf. The cells within the bramble are occu- 

 pied by cocoons, one of which is opened to show a nymph. 



Formerly most villages and country houses were covered with 

 thatch, and a stunted vegetation grew over the roofs, in which 

 many insects found very comfortable homes. Many may recollect 

 the pretty villages with their thatched cottages which were so 

 common before slates began to be used, and many naturalists 

 were aware that nearly every straw of those simple roofs was 

 the cradle of many a numerous family of little bees. Now-a- 

 days granaries and barns tell the same story, and little Osinice, 

 which have long and notched mandibles, make comfortable gal- 

 leries in the old straw. These insects are called Chelostonics, and 

 they are so small that the inside of a straw forms a spacious 

 gallery for them. Their strong mandibles are admirably adapted 

 for cutting into the straw, and when this is done the inside is 

 properly cleaned out, and cells are made within witli the aid of 

 a little mortar. It happened, therefore, in the olden time that 

 the labourers inside the cottages protected and gave lodging unin- 

 tentionally to hundreds of industrious and hard-working little bees. 



Some Hymcnoptera which belong to the bees are leaf cutters, 

 and have very long mandibles with four teeth upon them, and 

 they are the instruments for perpetrating this clever piece of work. 

 These bees are called McgacJiilidce, and the commonest species, 

 which is well known in every garden, and much dreaded in green- 

 houses, is McgacJiile centiinailaris. 



It is not a remarkable looking insect; in fact no one would 

 believe it to be gifted with so much intelligence by observing its 

 very humble exterior. These bees are smaller than hive bees, are 



