364 INSECTS AT HOME. 



Take, for example, Osmia hicolor. This insect generally 

 makes its cell within the empty shells of garden snails, not 

 because it is unalole to make a burrow, but because it finds the 

 empty shells to be as good as ready-made burrows. So it begins 

 by depositing an egg at the end of the whorl, putting in a suf- 

 ficiency of honey and pollen, and making a partition wall of 

 some vegetable substance. A second chamber is then formed in 

 like manner, and so on until the Bee has reached the mouth of 

 the shell, which it closes with a strong barrier. 



There is in the British Museum a very curious example of 

 sagacity in this Bee, showing clearly that the insect possesses 

 some share of reasoning powers as well as mere instinct. She 

 had taken the shell of the large garden snail, and when she came 

 near the mouth, found -that it was much too large. So, instead 

 of proceeding after the usual fashion, she has made two cells 

 and placed them side by side, and close to the mouth itself 

 has actually set the cells crosswise. 



As, in order to emerge into the air, it is necessary for the 

 inhabitants of the lower cells to pass through the others, this 

 necessity is met in a very simple manner. Those eggs which 

 are laid in the outermost cells produce males, and are developed 

 before the others, so that those insects which inhabit the cells 

 immediately beneath them can pass through their deserted 

 homes. 



Another species, Osmia leucomelana, burrows in bramble- 

 sticks, not taking out the whole of the pith, but scraping out a 

 series of chambers, which are connected by small passages, so 

 that the walls of division take but little material. 



Another species, Osmia fulviventris, makes its burrows in 

 decaying wood ; while another, Osm^ia parietana — a northern 

 species — chooses the under surface of stones. There is in the 

 British Museum a stone, measuring ten inches by six, on which 

 are no less than two hundred and thirty cells of this Bee. Mr. 

 F. Smith took charge of this mass of cells, and found that the 

 Bees escaped at intervals during three years. 'When found, 

 one-third were developed. The following year a second brood 

 came forth, and while in my possession a third. In the first 

 instance, the whole deposit was subject to the same influences 

 and had produced larvae ; what was the cause of the retarded 

 development of the rest, it were vain to attempt to determine-' 



