The insect usually makes her perforation a foot in depth, and divides this into eight, nine, or even twelve cells, each about five lines long, and separated by partitions formed by the gnawings of the pith, cemented by honey, or some similar glutinous fluid, much in the same manner with the _Xylocopa violacea_, which we have already described. [This species is probably _Ceratina cærulea_, as the second species, _C. albilabris_, seems to have little claim to be considered as a British insect. It is plentiful in spots where it resides, but is very local. It can best be found by collecting all the specimens of bramble branches that have holes bored into the pith. Mr. F. Smith says of this tiny bee, "Some years ago I observed a small bee most industriously employed in excavating a dead bramble stick. My attention was directed to the circumstance from observing some of the fallen pieces of pith on the ground immediately beneath. Occasionally fresh quantities of dust were pushed out. At length, the little creature came out of the stick as if to rest, and after sunning itself for a few minutes, it re-entered, and again commenced its labours. Later in the day, after stopping up the entrance, I cut off the branch and found in it a male and female ceratina." The ceratina is only the sixth of an inch in length, and is deep shining blue in colour. There are many other species of British bees which frequent the stems of bramble and other trees. One of them is known as _Prosopis signata_. The cells made by the bees of this genus are lined with a membrane, and are stocked with liquid honey. Some species will not take the trouble of boring a tunnel for themselves, but will make use of hollow stones, or similar localities, and place in them the silk-covered cocoons. There are species of that versatile genus _Osmia_ (_O. leucomelana_), in the habit of burrowing into dead bramble branches. The mother insect bores a hole some six inches in length, throwing the pieces of pith away, and then, depositing at the bottom an egg and a supply of food, she forms a cell by fixing across the burrow a stopper made of masticated leaves. The stopper retains its place firmly, because the bee does not eat away the whole of the pith, but alternately widens and contracts the diameter of the burrow, each contracted portion being the termination of a cell. The perfect insect appears in the early summer of the following year.] Carpenter-Wasps. [Illustration: A, B, represent sections of old wooden posts, with the cells of the Carpenter-Wasp. In fig. A the young grubs are shown feeding on the insects placed there for their support by the parent wasp. The cells in fig. B contain cocoons. C, Carpenter-Wasp, natural size. D, cocoon of a Carpenter-Wasp, composed of sawdust and wings of insects.]