INJURIES INDUCED BY PLANTS 



183 



that they open even in damp weather, whereas sound cones 

 remain tightly closed. This cone-disease occurs throughout the 

 whole of North Germany, reaching as far south as the spurs 

 of the Alps. 



^CIDIUM CONORUM PICE^ 



This cone-infesting fungus differs from the former by the fact 

 that only two large aecidia are situated on the outer side of 

 each scale of the spruce-cone. After the pale peridia have 

 ruptured and the spores have been scattered, pale spots are left 

 on the scales (Fig. 114). 



.ECIDIUM CORUSCANS 1 



When this rust-fungus, which is common on spruces in 

 Sweden and Finland, attacks a young shoot, the whole of the 



FIG. 115. A spruce-branch, one shoot of which, a, has developed normally, while 

 two shoots, 6, have been attacked by A. coruscans. All the leaves of the 

 diseased shoots are short and fleshy, and bear secidia on all their four sides. The 

 lower sides, c, and the upper sides, d, of a diseased leaf showing the secidia, 

 the peridia of which are still present at c, but have mostly disappeared at d. 



leaves are affected. They become occupied by a peridium, which 

 ruptures in places or along the whole length of the leaf, and 

 displays the golden yellow aecidia underneath. Such leaves 

 make the shoot look like a fleshy cone (Fig. 115). These " cones " 

 are eaten in Sweden under the name " Mjolkomlor." 



1 Reess, Die Rostpilzformen der deutschen Coniferen, p. 100. 



