446 



PROTECTION AGAINST FUNGI. 



round the shoot, the supply of water is then cut off, the needles 

 turn yellow, and the shoot dies towards the end of June or in 

 July, hanging down as if it were frozen. 



The plant, hy sending out several side-shoots at the base of 

 the lost leader, endeavours to replace it; but these shoots 



Fig. 216.— Part of a two- 

 year-old shoot, bent at 

 7 owing to the wounds 

 caused by Melampsora 

 pinitorqud, Rostrup. 



Fig. 217. — Crippled condition of a Scots piue shoot 

 wliich has been attacked by ^f. piiiitirrqKd for 

 several successive years. (^Reduced.) 



usually become infected in succeeding years. The mycelium 

 of the fungus grows in the green cortex and becomes perennial 

 in a plant which is once attacked, while sporocarps annually 

 appear in the spring-shoots, except in very dry springs. The 

 infected wood becomes brown down to its pith. 



