334* Linnean Society. [June 20, 



of your Society. Perhaps the following account of the habits of 

 this curious insect may interest you ; they are given from personal 

 observation. The male of the mason-bee is about twice the size of 

 the common wasp, but nearly of the same colours ; the thin portion 

 which unites the thorax and abdomen being nearly an eighth of an 

 inch in length, and scarcely thicker than a horse's hair. The female 

 is about one-eighth this size, and of a bright shining bottle-green, 

 like a blistering fly. She bears no resemblance to the male, and 

 they are only seen together when the eggs are being laid. Early in 

 October, so soon as the rains are fairly over, the mason-bee begins 

 to build. Having selected a spot for his nest, generally in some 

 quiet corner, to which however there is free access and egress, he 

 approaches with a piece of wet mud about the size of a pea, which 

 he holds with his fore-feet against his breast, close up to his mouth. 

 He first makes a neat thin ring, of about an inch in diameter, and 

 then brings this up by successive additions until it assumes very 

 nearly a spherical form. The opening at the crown is now drawn 

 up like the neck of a bottle, and turned over with a flat lip, an 

 opening being left of about an eighth of an inch in diameter. Two 

 or three of these little dwellings, which take from six to eight hours 

 to finish, are commonly built together and left to dry before any- 

 thing more is done ; the outer shell having in the process of con- 

 struction been partially filled with mud, and divided into compart- 

 ments, a considerable space being left open within the principal 

 aperture which gives entrance to them all. So soon as they are 

 firm enough, and whilst still damp, the female is seen running and 

 flitting about them, and dropping a few eggs in each ; and imme- 

 diately after this the male is seen to approach the nest warily with 

 what appears to be a cumbrous load in his arms. This turns out to 

 be a large green caterpillar, about three-quarters of an inch in 

 length, fully the size of the bee which carries it : this is now thrust 

 through the bottle-neck aperture into the nest. The struggles of 

 the resisting worm being met with many a punch, nip, and dig from 

 the inexorable bee, it seems at last to sting its victim to death. The 

 moment it is fairly within the bottle, a little globule of mud is 

 brought, and the mouth of it hermetically sealed. More bottles in 

 succession are built, provisioned, and sealed up in this way, till the 

 collection consists of six, eight, or ten ; when fairly completed, the 

 builder seems to take no more heed of them : he is shy and easily 

 frightened, and will abandon his operations and quit the house alto- 

 gether if he observes anybody near. I have never happened to see 



