A NEW SPECFES OP MULBERRY FUNGUS. 199 



it we can recognize the radial arrangement of tiio crystals. Prof. De 

 l>ary has described crystalline spheres of a similar nature found in the 

 narrow cylindrical hyphaä of the mycelium of Fhallus caniims.* 

 Crystals of calcium oxalate of other forms, such as regular quadrate 

 octohedra, rod-shape, &c., are also found in great abundance in the 

 same place where the crystalline spheres are found. 



The mycelia of the fungus form an em^rmous nnmber of 

 sclerotia in all parts of the diseased portion of the roots (PL. XXVII, 

 Fig. 1, (t). The sclerotia are irregularly roundisli bodies 1-4 mm. in 

 diameter, and are dark purplish brown in colour. If tlie nourish- 

 ment in the sap-containing layers of the host plant becomes scanty by 

 the parasitic action of the fungus, and also when the vegetative 

 activity of the host plant is diminished in autumn, the interior of the 

 lenticels and the interstices between the cork layers become filled with 

 the sclerotia of the fungus, while the mycelial strands which remain 

 outside spread widely on the surface of the roots. By carefully 

 detaching the mycelial strands we can ascertain that they have no 

 direct communication with the sclerotia. The number of sclerotia is 

 different in different parts of the roots, according to the degree of the 

 injury done by the fungus ; and the greater the degree of the injury, 

 the greater the number of the sclerotia. The formation of sclerotia 

 does not take place on the outside of the host plant, but always in the 

 inside or in the spaces partly exposed by the formation of fissures 

 (PL. XXYII, Fig. 2). The sclerotia have a dark l)rown rind (PL. 

 XXVII, Fig. 3, i), and a medulla of white soft tissue (Fig. 3, (i) with 

 a few air-conducting passages. The hyplia? of the medidla are 

 cylindrical and septate, anastomosing with one another in a rather 

 loose manner (Fig. 4, ci), and are 4-5 U. in diameter. Towards the 

 surface of the sclerotia, the medulla passes gradual I v into the rind, 



* De Bary, Vergl. Morphol. u. Biol. d. Pilze, Eng. traas. p, 11. 



