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development compared with the strong tissues found around the vascular 

 bundles of sound stems of the same age. Comparison was likewise made 

 of the inner tissues of healthy and affected stems, with regard to size, 

 age, progress of malady, etc. The conclusion reached was that the 

 affected stems have in most cases thin parenchyma and their fibrous 

 tissues around the vascular bundles have only an imperfect development. 



Under the microscope we find that in the affected stems the thick 

 fibrous layers around the vessels are reduced to thin ones by the attack 

 of the mycelium. Apparently, vessels can no more sustain the pressure 

 of liquid on their walls and admit the perculation of the liquid, which 

 otherwise would have remained in the vessels themselves, to be ultimately 

 accumulated in the hollow surrounded by tissues poor in vascular bundles. 

 On the other hand, the external tissues of the stem hardly admits the 

 percolation of the liquid which thus most naturally find its way into the 

 hollow. 



The tissues forming the lower part of the affected stem are inter- 

 laced with mycelium and naturally give easier access to the liquid than 

 the upper part. Since, however, the tissues of lower part of the stem are 

 strong and thick walled, they do not allow the percolation of the liquid in 

 large amounts, and large accumulations are moreover impossible in that 

 part of the stem. This shows that the percolation of the liquid depends 

 upon the thickness of surrounding tissues more than on the irregularities 

 of cell layers caused by the attack of mycelium. 



In Plate VIII. Fig. 4. is a micro-photographic representation of the 

 cross section of the affected root stem. The tissues are little distinguished 

 from those of the stem; when compared with healthy ones, they show 

 likewise traces of imperfect development. Roots are most easily attacked 

 by the mycelium both in the exterior and interior tissues and when they 

 are attacked by mycelium then they often have been prevented from 

 discharging their proper functions by interlacing mycelium. 



III. EfiFects of Malady and its Diffusion 



We have already described how the stems and roots of bamboo are 

 affected by the malady that they cannot perform their natural develop- 

 ment. The malady attacks the subterranean stems or roots of bamboos 

 at the time of sprouting. Once subterranean stem or roots are infested 



