478 



PROTECTION AGAINST FUNGI. 



apple, are also attacked. It is found in thickets 5 to 7 

 years old, but also in 100 years old woods, and is worst 

 amongst healthy smooth-barked trees. 



Infected branches eventually die, and infected trees in the. 



Fig. 232. Nectria ditissima, 

 Tul., on a beech. a Com- 

 mencement of the disease, 

 which has proceeded deeper 

 into the wood at b. 



Fig. 233. Canker on an oak caused by 

 Nectria ditissima, Tul. 



course of time assume extraordinary shapes, and are fit only 

 for firewood. 



The disease has been known since 1865 in the Saxon Erz 

 mountains and in the extensive beech forests in Hesse. It is 



