264 VEGETABLE FOES AND DISEASES 



the vegetation only partially decayed, may not contain 

 spores, yet afford a congenial means for those present 

 in the ground to germinate and reproduce themselves. 

 Hence when seeds or plants push rootlets the my- 

 celium of the fungus many assume its parasitic pro- 

 clivities. The use of quick lime also tends to resolve 

 the decaying animal and vegetable matter in the soil 

 into inorganic substances upon which no saprophyte 

 can live, hence to take away the food is to exhaust the 

 organism. Whether lime acts on fungus in that way 

 or directly destroys its saprophytic existence is not 

 clear, but that its application reduces infection to a 

 minimum is beyond question. 



Another matter worth notice is that plants grown 

 in pots are far less liable to sleeping disease than those 

 planted in the border upon which the pots are placed. 

 In the cultivation of plants in pots the compost mainly 

 consists of loam in which the organic substances are 

 in a complete state of decay, and fertilisers employed 

 which only green-leaved plants can make use of. 

 The fungus, therefore, even if present, cannot exist, 

 or if the spores germinate the mycelium has its career 

 ended in the saprophytic stage. 



As preventive the use of quick lime is strongly ad- 

 vised at the rate of one pound per square yard, slaking 

 with the smallest amount of water necessary to cause 

 it to fall into an apparently dry powder, then spread- 

 ing evenly whilst hot and in the course of a day or 

 two digging in with a fork and taking small spits so 

 as to mix as evenly as possible with the soil to the 



