2 34 PLANT LIFE. 



then bores its way down into the leaf and forms a fungus 

 tube or thread, which extracts food from the leaf cells, 

 and grows all through the tissues. Towards the end of 

 the potato season they grow down the shaw and attack 

 the young tubers. If these are planted, the young 

 plants are diseased from the beginning and are soon 

 killed by the fungus, but they may, of course, infect a 

 whole field of potatoes before they die off Nothing in 

 the nature of a cure is known ; but, of course, the selec- 

 tion of thoroughly sound tubers is of great assistance. 

 If the weather is very wet, the disease is always severe, 

 as the germination and movement of the zoo-spores is 

 greatly assisted by the water on the leaves. The leaves 

 are sometimes sprayed with Bordeaux mixture ; and, if 

 this is done in time, the progress of the blight may be 

 greatly limited. 



The Slime fungi {Myxomycetes or Mycetozod) are often 

 considered to be animals and not plants, but they are 

 generally placed amongst the fungi. Most of them are 

 to be found in dead or rotten wood, and they seem 

 specially adapted to destroy persistent tree stumps. 

 They are very difficult to distinguish unless when in 

 fruit ; but any rotting log of wood is pretty certain to 

 yield specimens from September to February, either 

 under the bark or upon the exposed surface. The fruc- 

 tifications are very small, but, when seen with a lens, 

 exceedingly neat and graceful. They vary greatly ' in 

 shape. Some are like pin heads ; others are the shape 

 of a champagne or wine-glass ; in many species the 

 heads run together forming whitish and curved convo- 

 lutions ; others are globular and may even be a quarter 

 of an inch or more in diameter. Lycogala miniatum, for 

 instance, is a dull olive brown, or pinkish grey to 

 reddish brown, and is extremely like a small Puff-ball. 



