GENERATION OF INSECTS. 21 



oi" the same colour, sometimes upon the branches of 

 the rose-tree, but more frequently, as we have ob- 

 served, upon some smooth object contig-uous. For 

 several successive seasons, we have found more than 

 one group of these eggs upon the glass panes, as 

 well as the frame- work, of a window, beneath which 

 a rose-tree has been trained. At present (January, 

 1830,) there are two of these groups on one pane, 

 and three on the frame-work ; and as each contains 

 about fifty eggs, should they all be successfully 

 hatched, two or three hundred caterpillars would at 

 once be let loose, and, streaming down simultane- 

 ously upon the rose-tree beneath, would soon devoar 

 the greater number of its buds. As this window faces 

 the east, the sudden appearance of the insects would 

 make it appear not unplausible that they had been 

 swept hither by an easterly wind. 



We found, during the same winter, an extraor- 

 dinary number of similar groups of the eggs of a 

 leaf-roller {Lozotceiiia Ribeana?) on the branches of 

 the gooseberry and red currant, in a garden at Lee. 

 On some small trees, from two to ten groups of eggs 

 were discovered ; and as each group consisted of 

 from thirty to fifty, a caterpillar might have been 

 hatched for every bud. After the severity of the 

 season was over, we had the piece of bark cut off 

 on which these eggs were attached ; and though they 

 had been exposed on the bare branches to the intense 

 frosts of 1829-30, they were hatched in a few days 

 after being brought into our study. As the currant- 

 trees were not then come into leaf, we had no food 

 to supply them with, and they refused the leaves of 

 all other plants which we offered to them. Had they 

 been permitted to remain on the trees till they were 

 hatched, they would probably have not left a single 

 leaf undevourcd. For this spring, at least, these 

 currant bushes will be safe from their attacks, and or 



