126 Bibliographical Notices. 



but in cultivated districts, particularly if the soil be clayey, it selects 

 a decaying tree, preferring the stump of an old willow ; it lays up a 

 store of pollen and honey for the larvae, which when full-grown spin 

 a tough dark brown cocoon, in which they remain in the larva state 

 until the autumn, when the majority change to pupse, and soon 

 arrive at their perfect condition ; many however pass the winter in 

 the larva state. In attempting to account for so remarkable a cir- 

 cumstance, all must be conjecture, but it is not of unfrequent occur- 

 rence ; this species also frequently makes its burrows in the mortar 

 of old walls. Osmia leucomelana may be observed availing itself of 

 a most admirable, and almost ready, adaptation for a burrow ; it 

 selects the dead branches of the common bramble ; with little labour 

 the parent bee removes the pith, usually to the length of from five to 

 six inches ; at the end she deposits the requisite quantity of food, 

 which she closes in with a substance resembling masticated leaves, — 

 evidently vegetable matter ; she usually forms five or six cells in one 

 bramble- stick. The bee does not extract the whole of the pith, but 

 alternately widens and contracts the diameter of the tube, each con- 

 traction marking the end of a cell ; the egg is deposited on the food 

 immediately before closing up the cell ; it is white, oblong, and about 

 the size and shape of a caraway-seed : the larva is hatched in about 

 eight days, and feeds about ten or twelve, when it is full-grown ; it 

 then spins a thin silken covering, and remains in an inactive state 

 until the following spring, when it undergoes its transformations, and 

 appears usually in the month of June. 



" Osmia hirta burrows in wood, seldom in any other material ; the 

 same habit will be observed in Osmia cenea ; but I have observed this 

 bee more than once constructing its burrow in the mortar of walls, 

 and sometimes in hard sand-banks. Osmia aurulenta and O. bicolor 

 are bees which commonly burrow in banks, the latter being very 

 abundant in some situations, forming colonies ; but although it ap- 

 pears to be the natural habit of these species to construct tunnels in 

 hard banks, with great labour and untiring perseverance, still we 

 find them at times exhibiting an amount of sagacity, and a degree of 

 knowledge, that at once dispels the idea of their actions being the 

 result of a mere blind instinct, impelhng them in one undeviating 

 course. A moment's consideration will suffice to call to mind many 

 tunnels and tubes ready-formed, which would appear to be admirably 

 adapted for the purposes of the bee — for instance, the straws of a 

 thatch, and many reeds ; and what could be more admirably adapted 

 to their requirements than the tubes of many shells ? So thinks the 

 bee ! O. aurulenta and O. bicolor both select the shells of Helix hor- 

 tensis and H. nemoralis : the shells of these snails are of course very 

 abundant, and lie half hidden beneath grass, mosses, and plants ; the 

 bees finding them in such situations, dispense with their accustomed 

 labour and take possession of the deserted shells. The number of 

 cells varies according to the length of the whorl of the shell selected, 

 the usual number being four, but in some instances they construct 

 five or six, commencing at the end of the whorl ; a suitable supply 

 of pollen and honey is collected, an egg deposited, and a partition 



