COLLETES. 189 



sometimes less. Now comes into operation the use of 

 the peculiarly-formed tongue with which nature has 

 furnished them, and described above in the generic cha- 

 racter. These cells are occupied by a succession of six, 

 or eight, or even sometimes no more than two, three, or 

 four cartridge- or thimble-like cases, in each of which 

 is deposited a single egg with a sufficiency, taught the 

 creature by its instinct, of a mingled paste of honey and 

 pollen, for the full nurture and development of the vermi- 

 cle that will proceed from the egg upon its being hatched, 

 and wherein this larva, having consumed its provender, 

 becomes transformed into the pupa, and by the con- 

 tinuance of nature's mysterious operations, it speedily 

 changes into the perfect insect. But the beauty with 

 which these little cells are formed transcends conception. 

 Each consists of a succession of layers of a membrane 

 more delicate than the thinnest goldbeater's skin, and 

 more lustrous than the most beautiful satin. In glitter 

 it most resembles the trail left by the snail, and is 

 evidently, from all experiments made, a secretion of the 

 insect elaborated from some special food it consumes, and 

 by means of its bilobated tongue, which it uses as a trowel, 

 it plasters with it the sides and the bottom of the tube 

 it has excavated to the extent necessary for one division. 

 As this secretion dries rapidly to a membrane it is 

 succeeded by others, to the number of three or four, 

 which may be separated from each other by careful 

 manipulation. It then stores this cell, deposits the egg, 

 and proceeds to close it with a covercle of double the 

 number of membranes with which the sides are fur- 

 nished, and continues with another in a similar manner, 

 until it has completed sufficient to fill the tubular cavity, 

 which, after closing the last case similarly to the rest, it 



