Carpenter-Bees. 61 



wild-rose which has been accidentally broken, and digs into 

 the pith only, leaving the wood and bark untouched. Her 

 mandibles, indeed, are not adapted for gnawing wood ; and, 

 accordingly, he found instances in which she could not finish 

 her nest in branches of the wild-rose, where the pith was not 

 of sufficient diameter. 



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 ccerulea, 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 excavat- 

 ing 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. 



