164 



MANUAL OF TREE DISEASES 



larch and pine in the United States. The symptoms in fir are 

 similar to those in spruce which are described on page 324. The 

 pockets are larger than those fomid in spruce and the wood is 



Fig. 23. — Pecky wood- 

 rot ; early stage in Doug- 

 las fir. 





Fig. 24. — Pecky wood-rot in 

 Douglas fir. 



largely destroyed. In Douglas fir the pockets are at first cir- 

 cular white areas (Fig. 23). Later the pockets increase greatly 

 in niunber and finally the wood is honeycombed (Fig. 24). 

 Somewhat different symptoms are shown in larch and pine and 

 are described on pages 215 and 291 respectively. 



The life-history, dissemination of the spores and mode of in- 

 fection of the wood-rotting fungi are treated in a general discus- 

 sion on page 64. 



