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Signs of the Young Deodar trees 6-15 feet in height are chiefly attacked. 

 One tree generally dies first and then the disease spreads to 

 others near it, gaps being formed which quickly extend cen- 

 trifugally. Resin at first begins to e%ude from different 



o / o 



points along the stem and then the needles turn yellow and 

 fall off. Stems usually take two years to die completely. 



The sporophores or fruiting organs are developed at the base 

 Life-History of the Deodar stems and will also probably be found 

 and Damage O n the roots below the ground surface. They arise from 

 done. cushions of mycelium which force their way to the 



surface of the stem or root at these points, where the sporo- 

 phores first appear as small, rounded, chocolate -brown 

 nodules. These increase in number and run together forming 

 a brown incrustation broken by numerous ledges and tuber- 

 cles. On the younger portion of the sporophore a series of 

 imbricate bracket-like protrusions are developed. The lower 

 surface of these brackets is white and contains numerous 

 minute pores, on the walls of which the spores are developed, 

 while the upper surface is rough, brown, and covered with 

 tubercles and concentric ridges. It is probable that these 

 spores are often carried in the ground on the fur of mice and 

 other burrowing animals and are rubbed off on healthy roots. 

 On germination they give rise to very delicate hyphse which 

 penetrate between the bark scales, force their way into the 

 wood and give rise to characteristic white sheets and bands 

 of mycelium, between and under the bark scales. The roots 

 are not the only parts affected. Broad bands of the 

 mycelium invade the collar, ascending the stem and forcing 

 their way along the cambial layer, in feathery strands of 

 snow-white tissue. These completely destroy the cambial 

 layer. In addition to this the wood is directly attacked 

 and destroyed by the minute hypha3 which bore their way 

 from cell to cell by means of a cellulose-dissolving enzyme 

 which they exude. The lignin in the cell-walls of the 

 attacked wood is dissolved out first by the hyphae and 

 the middle lamella is destroyed, so that the wood 

 elements fall apart. As a result of this action white areas 

 of diseased wood arise which are very characteristic and which 

 are usually elongated in the direction of the long axis 

 of the stem. They consist of dissociated cells of prac- 

 tically pure cellulose, which, being themselves ultimately 

 decomposed, leave small hollows in the wood. Before de- 

 composition is completed the cell-walls show a fine striation 

 and, later, large spiral cracks. Living cells in the wood paren- 



