258 



Bulletin 193. 



not show the pockets, since the soft wood is so readily fractured 

 by the teeth of the saw. But when the end of a block is planed 

 off smooth the pockets in transection are quite distinctly brought 



to view. They are shown in the photograph. 

 From a side and end view shown in the photo- 

 graphs the pockets are seen to be oblong in side 

 view and cylindrical in cross section. Tliey are 2 

 to 3 nnn. broad and 4 to 6 mm. lono^. In the 

 younger portions of the trunk, some distance above 

 the size where Jogs were cut, and below the point 

 of entrance of the fungus, and thus nearer it, the 

 pockets were not yet formed. This is probably 

 due to the fact that while tlie mycelium first pene- 

 trated the heart wood here, tlie latter being younger 

 was more resistant, and the 

 process of disintegration pro- 

 ceeded less rapidly. The 

 23ockets aj^pearing on cer- 

 tain of the branches is ac- 

 counted for by the fact 

 that these branches had been 

 killed for some time, and 

 were consequently in a less 

 resistant condition. 



The formation of pockets 

 by the rapid disintegration 

 of the tissues at many cen- 

 tres recalls the "peckiness" 

 of cypress wood caused by 

 the mycelium of a fungus yet 

 unknown. The pockets in 



the cypress wood are much larger, however, and 

 the structural character of the affected wood is 

 quite different. In the case of the cypress trunks 

 affected with this disease known as " peckiness," 

 it is believed that tlie fungus, while developing at the 

 centres, excretes an enzyme or " ferment," which permeates the sur- 

 rounding wood and acts as an antiseptic which prevents the further 



92.— BesuU of 

 bad pruning 

 of hickory, 

 the limbs have 

 rotted out 

 allowing en- 

 trance of 

 fungus my- 

 *» celium. 



93. — Proper way to prune, 

 wounds healing up 

 properly. 



