530 LIFE AS RELATED TO PHYSICAL CONDITIONS 



effect upon the fauna (animals) and flora (plants) of a 

 country. 



The species that thrive in a region must have adapted 

 themselves to the existing conditions, yet other animals 

 and plants may be as well adapted for certain regions as 

 those now inhabiting them. Striking examples of this 



CALIFORNIA RABBIT DRIVE 



In some localities rabbits become such a pest that the inhabitants turn 

 out in a body, drive them into inclosures, and kill them. 



are the English sparrow and the gypsy moth, which have 

 spread with such tremendous rapidity since their introduc- 

 tion into this country. The rabbit in Australia and southern 

 California is another striking example. The adaptability 

 of plants to a new region is also illustrated by the Russian 

 thistle which was introduced into this country in 1873 and 

 which has now become a national pest. 



