Mans Work on the Farm 357 



fields. So extremely troublesome are some of these, 

 of the thistle tribe, that laws are passed to ensure their 

 being cut down, and fines are inflicted, in some parts, of 

 a dollar per plant if they are allowed to ripen their 

 seed ; while so desperate is the battle felt to be, that, 

 in Manitoba, persons who do not cut them down 

 within five days, after they have been warned, are 

 fined i a day. Station-masters are held responsible 

 for the weeds on railway property; and seed-merchants 

 convicted of selling seed containing any admixture of 

 wild oats, wild mustard, or ' Canada-thistle/ are fined 

 from -2 to 20. Nevertheless, in spite of the war 

 waged against it, the last of these is a ' pest ' on all 

 badly cultivated farms, and renders some of the country 

 roads of Ontario almost impassable. 



But now to consider briefly some of the vegetable 

 changes which have taken place in other parts of the 

 globe. The last of these have been due to the 

 discovery of Australasia, where all the crops now 

 cultivated, as well as many which are not cultivated, 

 are foreign importations from Europe, Asia, and 

 America, for Africa has supplied few emigrants. 



None of the plants grown by the natives had oeen 

 sufficiently improved to make them worth cultivating 

 by Europeans ; and the only useful plant which 

 Australia has given to the rest of the world is the 

 eucalyptus, which seems already to belong to the 

 Mediterranean as much as the olive, cactus and aloe. 



In Australia, as elsewhere, man has had to find out 

 by experience how hazardous it is to bring colonists 

 into a new and comparatively unoccupied land, unless 

 he is sure he can control them. It is not only in the 

 matter of rabbits that he has discovered his mistake. 



