I DASYGASTRES— LEAF-CUTTING BEES 5 I 



work in a series of glass tubes that he placed on a table in his 

 laboratory. He marked various individuals, so that he was able 

 to recognise them and note the progress of their industrial works. 

 Quite a large number of specimens thus estal^lished themselves 

 and concluded their work before his very eyes. Some individuals, 

 however, when they had completed the formation of a series of 

 cells in a glass tube or in a reed, had still not entirely completed 

 their tale of work. It would be supposed that in such a case 

 the individual would commence the formation of another series 

 of cells in an unoccupied tube. This was not, however, the case. 

 The bee preferred tearing open one or more cells already completed 

 — in some cases, even by itself — scattering the contents, and de- 

 vouring the egg ; then again provisioning the cell, it would deposit 

 a fresh egg, and close the chandjcr. These brief remarks will 

 perhaps suffice to give some idea of the variety of instinct and 

 habit that prevails in this very interesting genus. Friese observes 

 that the variety of habits in this genus is accompanied as a rule 

 by paucity of individuals of a species, so that in central Europe 

 a collector must be prepared to give some twenty years or so of 

 attention to the genus before he can consider he has obtained all 

 the species of Osmia that inhabit his district. 



As a prelude to the remarks we are about to make on the 

 leaf-cutting bees of the genus Megachih it is well to state that 

 the bee, the habits of which were described by Eeaumur under 

 the name of " I'abeille tapissiere," and that uses portions of the 

 leaves of the scarlet poppy to line its nest, is now assigned to 

 the genus Osmia, although Latreille, in the interval that has 

 elapsed since the publication of Eeaumur's work, founded the 

 genus Anthocopa for the bee in question. Megacliile is one of 

 the most important of the genera of the Dasygastres, being 

 found in most parts of the world, even in the Sandwich 

 Islands ; it consists of bees averaging about the size of 

 the honey-bee (though some are considerably larger, others 

 smaller), and having the labrum largely developed ; this organ is 

 capable of complete inflection to the under side of the head, and 

 when in the condition of repose it is thus infolded, it underlaps 

 and protects the larger part of the lower lip ; the mandibles 

 close over the infolded lal)rum, so that, when the Insect is at rest, 

 this appears to be altogether absent. These bees are called 

 leaf-cutters, from their habit of forming the cells for their nest 



