110 THE POPLAE AND THE WILLOW. 



also the abele and the aspen. Besides these Euro- 

 pean, or at all events Old World forms, there being 

 reason to believe them originally Asiatic, there are 

 several species indigenous to North America. All, 

 except the latter, agree in the curious peculiarity of 

 having their petioles laterally compressed at the ex- 

 tremity next to the blade. Hence arises that in- 

 cessant fluttering which has made a proverb of the 

 aspen, and which finds mention even in the 

 sacred records, though apparently connected, 

 through a mistranslation, with an entirely differ- 

 ent tree. " When thou shalt hear a sound of going 

 in the tops of the mulberry-trees," should by 

 right be "in the tops of the poplar-trees." Placed 

 alongside of the leaves of their near relations, the 

 willows, poplar leaves are found to be, as a rule, 

 scarcely longer than broad, where widest ; the 

 leaves of willow-trees, on the other hand, as a rule, 

 excel considerably in length. It is worthy of notice 

 too that while the leaves of poplar-trees are exceed- 

 ingly prone to become vegetable skeletons, lying 

 as they do, in this condition, often by hundreds 

 where poplar-trees abound, and found even in sub- 

 urban gardens, those of the willow decay in every 

 part at once, and yield none of the delicate tracery 

 so remarkable in the others. Lastly, there is a curious 

 contrast in the aspiring tendency of the poplar, 

 and in the " weeping " inclination, not only of the 

 famous willow of Babylon, but in several other re- 



