472 PROTECTION AGAINST FUNGI. 



c. Protective Measures. 



Underwood, and diseased branches and twigs, should be 

 removed by clearing, pruning and cutting off twigs with 

 shears. 



24. Herpotrichia nigra, E. Hrtg. 



(Spruce Black Needle-rust.) 

 a. Description and mode of Attack. 



The grey mycelium of Herpotrichia nigra, E. Hrtg., forms 

 an irregular, dark coat on twigs and needles of the spruce, 

 the mountain pine, and the juniper, up to about a meter from 



the ground. 



b. Subjects of A ttacJc, and Distribution. 



This fungus occurs in the Bavarian Alps only in mountains 

 where snow lies long, and there is very deadly, natural 

 regeneration being sometimes entirely prevented ; it is less 

 hurtful at lower altitudes. It covers the young plants, in 

 seed-beds, under the snow, to such an extent that in spring 

 they cannot remain upright. It also does much damage to 

 mountain pine. Juniper is also attacked. 



c. Protective Measures. 



i. No nurseries should be made where snow lies deep in 

 mountains. 



ii. Plant close to the stumps of felled trees. 



D. Fungi attacking Cones. 



25. Aecidium strobilinum, Alb. et Schw. 



(Spruce-cone Fungus.) 



This fungus develops its mycelium in the still green scales 

 of spruce-cones and destroys them. The hemispherical brown 

 aecidia are crowded together on the inner surface of these 

 scales. 



The infected cones which have fallen to the ground may be 

 easily detected by their opened-out appearance. Spores enter 

 the young cones early in spring. The teleutospores are not 

 yet known. The disease occurs wherever spruce is grown. 



Another fungus, Aecidium Conorum Piceae, Ess., also affects 

 spruce-cones, and may be distinguished from the above by 



