19S 



N. TANA K A. 



surrounded by finer ones wliich liave been produced by its ramifica- 

 tion (PL. XXVI, Fig. 3). As the strand grows, the branches of the 

 original hypha also ramify ; and the secondary branches thus produced 

 surround the primary branches, just as the latter surround the 

 original hypha. In this way branches of higher orders are succes- 

 sively produced, and surround the branches of the next lower order. 

 Ordinarily the branches of the liyjiha^ grow in one direction, but 

 occasionally there are found those that grow in two opposite directions 

 from the point of origination (PL. XX\^I, Fig. 4). The older 

 hyphai or those lying towards tlie center of the strand are much 

 more darkly coloured than the younger or those of the periphery. The 

 mycelial strand of the fungus is found only on the surface of the host. 

 When it makes its way into the tissues of the latter it usually forms 

 longitudinally elongated masses, such as are seen in the interstices be- 

 tween the cork layers of the host (PL. XXVI, Fig. 9). Similar mass- 

 es are also found on the surface. These masses of the hypha3 spread 

 widely in the cambium zone and in the yourjg bast, forming membrane- 

 like expanded networks of wliitish mvceli:i. These mycelia send out 

 single colourless hypha*, L5-1 U. in dinmcter (PL. XXVI, Fig. 5), 

 into the rind and wood, and especially into the dotted vessels. They 

 also send out masses of coloured hypha3 to the surface of the host, 

 from which are again developed ordinary external mycelial strands. 



Crystalline spheres of calcium oxalate, ^-\ mm. in diameter 

 (PL. XXVI, Fig. 6), are found in great numbers on those places 

 where the white mycehal membranes abound. They consist of an 

 enormous numher of somewhat radially arranged wedge-shaped 

 crystals (PL. XXVI, Figs. 7, 8), ench of which is 20-30 u. long and 

 10-15 n. broad. If we examine one of these crj'stalline spheres 

 under the microscope, taking care not to crush it, we see only the 

 sides and broader ends of the wedge-sha[)ed crystals ; and by crnsliing 



