96 THE BANANA 



form of this fungus matter, has caused to be segregated 

 round it. When they involve the roots of growing plants, 

 such as those of the banana, these succumb to their 

 attacks, and the plants themselves fail to thrive. One of 

 these stone-making fungi has been described, occurring in 

 South Australia.* 



When these masses are detected in the soil, they should 

 be dug out and thrown upon a fire, so as to raise them to 

 a high temperature. A solution of sulphate of iron applied 

 to the soil in which they occur may destroy the fungus 

 growth. 



(2) Another fungus attacks the banana in Australia 

 through its root system a kind of toadstool, probably 

 Armillaria mellea, that commonly occasions Tree Root 

 Rot. In this case the plant ceases to thrive, the stems are 

 short and slender, and the foliage yellowish and unhealthy- 

 looking. On digging up the stool, white threads (strands 

 of mycelia or rhizomorphs) are seen traversing it in all 

 directions, and giving off a decided fungus odour. A 

 section of the stool itself will discover these threads also 

 occurring within the tissue of the older portions, small 

 cavities now occurring, being white in consequence. These 

 parts, too, are dead and of a brown colour, with numerous 

 dark particles disseminated throughout them. 



When this trouble occurs, the plant should be dug out 

 and burnt, and the soil for a foot or two around removed 

 and sterilized by heat, or receive a generous application of 

 fresh lime that is to be dug well in. 



As a rule this root-fungus only occurs where the bananas 

 have been planted in newly felled land, and, originating 

 in certain decaying roots that still lie in the soil, it passes 

 to the root-stocks of its victims, being enabled to establish 

 injurious relations with these when growth has been 

 interfered with by dry weather or other physical causes. 

 It commonly persists for a long time in a spot in which it 

 has once manifested itself, attacking plant after plant, as 



* McAlpine (D.) and Tipper (T. G. O.), " A New Australian Stone- 

 making Fungus " : Trans. Ray. Soc. Victoria, 166, 3 plates (1894). 



