HABITATIONS OF INSECTS. 445 



in the ground or in the trunk of a rotten willow-tree, or 

 occasionally in other decaying wood. This cavity she 

 fills with six or seven cells wholly composed of portions 

 of leaf, of the shape of a thimble, the convex end of one 

 closely fitting into the open end of another. Her first 

 process is to form the exterior coating, which is com- 

 posed of three or four pieces of larger dimensions than 

 the rest, and of an oval form. The second coating is 

 formed of portions of equal size, narrow at one end but 

 gradually widening towards the other, where the width 

 equals half the length. One side of these pieces is the 

 serrate margin of the leaf from which it was taken, which, 

 as the pieces are made to lap one over the other, is kept 

 on the outside, and that which has been cut within. The 

 little annual now forms a third coating of similar mate- 

 rials, the middle of which, as the most skilful workman 

 would do in similar circumstances, she places over the 

 margins of those that form' the first tube,' thus covering 

 and strengthening the junctures. Repeating the same 

 process, she gives a fourth and sometimes a fifth coating 

 to her nest, taking care, at the closed end or narrow ex- 

 tremity of the cell, to bend the leaves so as to form a 

 convex termination. Having thus finished a cell, her 

 next business is to fill it to within half a line of the ori- 

 fice, with a rose-coloured conserve composed of honey 

 and pollen, usually collected from the flowers of thistles ; 

 and then having deposited her egg, she closes the orifice 

 with three pieces of leaf so exactly circular, that a pair 

 of compasses could not define their margin with more 

 truth ; and coinciding so precisely with the walls of the 



