144 FLOWERLESS PLANTS 



are noteworthy for the rapidity of their growth. 

 In some tropical species it has been observed 

 that these fungi will grow at the rate of two or 

 three inches in an hour. 



In connection ^^'ith the growth of fungi the 

 habit of many kinds of spreading out in a 

 circular fashion and forming the well-kno^\'n 

 " fairy rings " calls for comment. This is 

 pecuHarly noticeable in the case of many 

 Agarics, but the phenomenon is by no means 

 confined to these fungi. The happening is 

 really due to the way in which the mycelium 

 of the fungi spreads out more or less evenly on 

 all sides from its original starting point. In 

 some the manner of growth may be in the form 

 of a verv complete circle, whilst again it ma}' 

 be only a section of the arc. It is generally to 

 be observed that the grass and herbage inside 

 and parallel to the fungus ring is often of a 

 very bright green colour and of great luxuri- 

 ance. In some cases this is undoubtedl}' due 

 to the nutriment provided by the deca}' of 

 the last line of fungi. In many of the Agarics 

 this does not apply, however, seeing that these 

 fungi are positively harmful to and will even 

 kiU grass, on the roots of which they are para- 



