9.8 THE UNIVERSE. 



gions descend in frightful numbers on certain plants and 

 trees. According to Ratzeburg, the pine-tree alone serves 

 as a refuge for more than 400 species, the greater part of 

 which are hurtful to it; and Charles Miiller tells us that 

 the oak extends its hospitality to upwards of 200 kinds of 

 insects which are united to it by their parasitic existence. 



45. The Py rails of the Vine in its different stages : Pyralis strigulalis. 



Certain velvet - winged Phalenoe, notwithstanding that 

 they seem so harmless as they fly by night, in a short space 

 of time devastate the most magnificent forests of Coniferae, 



