HARMFUL TO CROPS. 233 



It is therefore thought that these aphides may 

 be the indirect cause of several plant fungi 

 diseases, such as smut, etc. 



In certain summers the writer has seen heavy 

 streams of this sticky substance fall from the 

 trees attacked. 



Club Roots. You must often have heard the 

 expression, " Oh ! the roots are clubbed ; " and 

 if you pull up one of these clubbed roots you 

 will find that the main root is much dwarfed, 

 whilst the side roots are often swollen into 

 spindle-shaped masses, so that the popular name 

 for the disease, Finger and Toe, is very appro- 

 priate. 



This disease is more often found on the 

 heavier and richer soils. It is caused by a slimy 

 fungus. The spores of this fungus by which it 

 propagates its kind are very small. 



From the soil, by means of the root hairs of the 

 cruciferous plants, namely, tur- 

 nips, cabbages, cauliflowers, 

 rape the spore finds its way 

 into the plant, and very quickly 

 produces slimy masses of fungi 

 that live on the vital parts of 

 the plant. 



The worst of the disease is, that it is difficult 

 to get it out of the soil when once it becomes 



o 



established. Perhaps the best remedy is to grow 



CORN SAW FLY. 



