EXOTIC FERNS I29 



The green aphis is another common pest 

 especially in love with a certain graceful 

 pteris. But it usually succumbs to confined 

 tobacco fumes. 



Red spider now and then dots the pale 

 green side of the holly fern (Cyrtomium), but 

 it is not difficult to exterminate, as the red 

 mites abhor water. 



The tiny white worms and black flies in 

 the soil, which seem to be forever swapping 

 identities, are more difficult to exterminate. 

 A little ammonia or lime in the water has a 

 wholesome effect, and common phosphate 

 sprinkled on top of the soil before watering 

 seems to make them gloriously ill. Much 

 of this trouble may be avoided if the soil is 

 thoroughly sterilised. 



There has been a great increase in the 

 popularity of exotic ferns in recent years. 

 A glance at shady nooks or secluded corners 

 in public and private parks shows that native 

 genera have by no means a monopoly of out- 

 of-door culture, but that many imported 

 species hitherto supposed to serve only for 



