76 THE POPLAR. 



nerves, placed parallel, and acting in unison with 

 each other ; but towards the base the stalk becomes 

 round, and then the nerves assume a triangular 

 form, and constitute three distinct supports and 

 counteractions to each other's motions. I know no 

 petiole with a similar conformation, or better cal- 

 culated for the vibration of a leaf. The leaf-stalks 

 of plants are very curious constructions ; and the 

 nerves and vessels contained in them, which are 

 the vehicles of a large portion of that nourishment 

 which plants receive through their foliage from the 

 air, seem in general differently placed, and fitted 

 for variety of operation. The poplar is a tree that 

 occasions at times a great deal of trouble in our pas- 

 ture lands, by the tendency which it has to extend 

 its roots, and throw out suckers. Three or four of 

 this species in a hedge-row, bounding a meadow in 

 my occupation, oblige me every year that the field 

 is mowed, by their prolificacy, to send a man with 

 his stockaxe to remove their numerous offspringing ; 

 a mere temporary expedient, tending rather to in- 

 crease the complaint, as eradication by trenching 

 with the spade can alone effectually check the en- 

 croachments of runners so tenacious of life, and 

 rapid in growth. 



The dyer's broom (genista tinctoria) abounds 

 with us, and becomes a perfect incumbrance in our 

 clay land pastures. It is seldom eaten by cattle, 

 except in cases of great necessity, and remains 



