WHY DOES E VIL EXIST? 77 



winter. What part, then, do they fulfil in the economy of 

 creation? An ambitious, but not a novel question, which 

 has often been propounded in reference to our parasitical 

 insects. 



The best answer which we can make to it is this : Every- 

 thing invites us to work. Labour is imposed even upon 

 him who least desires it. Earth will yield a return only in 

 proportion to the care we bestow upon her. 



If, after having toiled and sown, we had nothing to do 

 but to gather in the harvest, every person would become 

 an agriculturist. But a soil which is not manured will 

 soon grow exhausted ; and if it be neither ploughed nor 

 harrowed, instead of barley or vegetables, it will soon be 

 covered with tares ; rank weeds will flourish in every field. 

 Such is the chastisement reserved for sloth, the true " original 

 sin " of the human race. 



Well, then, it is among the weeds, everywhere so com- 

 mon, that we meet with the plants best able to brave the 

 rigours of frost. 



THE DOG MERCURY. 



The annual Dog Mercury (Mercurialis annua) is one of the 

 most tenacious. It attracts the passer-by, if he condescend 

 to bestow a glance upon it, only by its extreme abund- 

 ance ; it propagates very largely, though it is by no means 

 partial to all localities. For instance, it avoids the woods 

 as persistently as its congener, the common Dog Mercury 

 (Mercurialis perennis) seeks them. It prefers the vicinity 



