HARDWICKE'S SCIENCE-GOSSIP. 



273 



Then hovering about the bush with a continuous 

 hum it flies from leaf to leaf, apparently with a 

 selective impulse, choosing that leaf best adapted to 

 its purpose, and, having alighted upon the edge of 

 the selected one, commences cutting with its shearlike 

 jaws inwards from the edge about a quarter of an 

 inch, then making a sharp curve, cuts parallel with 

 the midrib for a distance of one-half to three-quarters 

 of an inch ; simultaneously with this cutting it rolls 

 the leaf between its legs in such a manner that only 

 the narrow surface of the edge of the leaf opposes its 

 flight, and again another curve is made at right angles 

 to the parallel cutting, and it goes on shearing until 

 all is severed but about the eighth of an inch ; then 



Fig. 161.— Section of cell of 

 Megachile Willoiighbiella, 

 showing egg in situ when 

 first deposited. 



Fig. 163. — Cocoon and 

 pupa of Megachile 

 Willoughbiella., 



Fig. 160.— Section of a flower-pot, showing the arrangement of 

 the cells in the burrow. 



Fig. 162. — Larva of Meg- 

 achile W 'illoughbiella 

 fully developed. 



poising itself upon its wings, in a few moments the 

 last operations are completed, and with a soft con- 

 tented hum it soars away with its treasure to a spot 

 exposed to the sun, evidently to relax the piece of leaf 

 that it may be the better moulded into the desired 

 shape, and after resting for a period of from five to 

 ten minutes it betakes itself to its burrow. In this 

 manner the miniature builder brings leaf after leaf, of 

 a similar shape and size, always taking them to the 

 same relaxing spot, from which it steers itself with 

 every successive piece of leaf by the same course to its 

 burrow. In the latter it arranges them in the form of 

 a short tube, in such a manner that the joint of the 

 upper layer does not come opposite that of the one 

 beneath it, but they are alternate as the joints of the 



slates of a house, so that as these curved pieces of leaf 

 dry they contract into a substantial leafy receptacle 

 for the offspring. This selecting, cutting and mould- 

 ing of parts it repeats eleven or twelve times to con- 

 struct the walls of a single cell, and occupies about 

 five minutes in arranging each piece in its burrow. 

 When the cell is ready for the reception of the pol- 

 len and honey the bee revels among the flowers that 

 secrete the necessary food, which it carries upon its 

 thighs and ventral side of its abdomen until it has 

 stored sufficient to half fill the receptacle. Then in 

 the centre of the cell, on the surface of the store of 

 food is deposited a single egg of a pear-shaped form, 

 a pearly lustre, and of the consistency of a globule of 

 gelatine. 



The egg gradually sinks into the pollen, but as it 

 sinks it bends over so that the more extended surface 

 which it offers prevents it from being wholly sub- 

 merged in its food, or that food which is to support 

 its life would be the means of destroying it. 



The mother bee now has recourse to the leaves 

 again for the purpose of covering the cell up. Away 

 she goes apparently with the foreknowledge of what 

 she is about to do, though probably for the first time 

 in her life ; nevertheless she alights upon a leaf 

 (perhaps the same one from which she obtained a 

 piece for the walls of her cell) and commences cutting 

 a circular piece this time, and so round that a pair of 

 compasses could not have defined it with greater 

 accuracy. However, it is not always that she is so 

 accurate ; mistakes occur both in the oval-shaped 

 pieces that form the walls of her cell and in the 

 circular pieces which compose its roof ; but, ap- 

 parently with the power of choosing those pieces 

 that are capable, and those not capable of being 

 shaped into cells, she disregards all those in which 

 she is unsuccessful and commences to cut fresh ones. 

 These errors are repeatedly to be seen on those trees 

 or shrubs visited by the insect for obtaining the 

 materials to construct its cells. Four or five of these 

 circular caps are brought to the burrow, and the edge 

 of each disc is turned up as they are laid in the cell, 

 the result being that when they dry the contraction 

 causes the turned up edge to bite tightly the inner 

 portion of the cell. For obviously if the disc be put 

 in the cell without being thus shaped, as it becomes 

 dry it would also become smaller and looser ; whereas 

 it being shaped, the drier it becomes the greater is 

 the tendency for the perpendicular edge to become 

 horizontal. Above the last cap is left a shallow 

 cavity for inserting the base of the succeeding cell, 

 and the like is observed with the one following it, 

 and so on till the last cell in the burrow is laid. 



The number of these cells varies greatly sometimes ; 

 there are as many as a dozen, and sometimes there 

 are only three or four. The diversity in these 

 numbers seems to accrue from the conditions by 

 which they are surrounded. If the burrow be a 

 short one, the bee will probably be satisfied with 



