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I. Morphology of Parasite 



The fungus which infects " Sugi " leaves is wanting in stroma ; its 

 presence is always characterised by dark minute spots noticeable to the 

 naked eye, which are nothing but the opening of the picnidium. The 

 picnidium is immersed in epidermis, 120-140p. in diameter, the wall 15-19f> 

 thick; spore one celled, round, sometimes, ovoid or elliptical, colourless, 

 8-10.5p. in diameter. The mycelium is, as a rule, hyaline. But on examing 

 the tissue of the dark brown part in the infected leaves, the mycelium 

 was found to be dark brown or yellowish brown and with numerous septa 

 having often an appearance of beads. 



II. Classification of the Fungus 



The fungus of the red plague belongs to Sphaeropsidales of Fungi 

 Imperfecti. As to further subdivision, according to the classification 

 hitherto known, one must assign it either to Phyllosticta or Phoma or 

 Macrophoma. This classification is based on the size of spores and the 

 part of plants affected by fungi. Thus, fungi that bear the spores above 

 15p. in diam. are classified as Macrophoma; below 15,u. as Phyllosticta, so 

 long as they attack leaves; while those that infest other parts of the 

 plant are classified as Phoma. In other respects, especially in morphology, 

 the three are altogether alike. As we have just said, Macrophoma is 

 nothing but the designation given to fungi bearing spores above 15p. in 

 diam; but the distinction is illogical, since that spores contained in one 

 and the same picnidium are always dissimilar in size. How can a species 

 bearing spores of 14-16fji in the same picnidium classified? It may be 

 classified as Macrophoma considering that spores above 15,a are con- 

 tained, or it may again reasonably be classified as Phoma when spores 

 below 15.U. are contained. In view of this fact, we do not see any parti- 

 cular need of classifying as Macrpohoma expressly. Again, we do not see 

 any need to make particular distinction between Phyllosticta and Phoma^ 

 simply because the former attacks leaves while the latter does not. It 

 has been customary among mycologists to group parasites which attack 

 needle leaves as Phoma, in consideration of the fact that leaves of conifers 

 resemble twigs of other trees but such a distinction can never be called 

 a scientific one. 



