109 



Symptoms. 



When the seedlings are attacked, brown spots appear on the 

 leaves. The spots increase in size and frequently become confluent,, 

 so that nearly the whole area of the leaf may become brown. The 

 remaining part of the leaf becomes yellow, and the leaf withers and 

 dies. The death of the leaves is follow^ed by the withering of the 

 young part of the stem, and, finally, by the death of the seedling. 



Both young and old leaves may become spotted. 



Sometimes, the seedling throws up a new shoot from below. The 

 actual fate of this shoot is unknown. 



The Fungus: " 



Material of all stages of the disease has been forwarded to the- 

 Agricultural Department for examination. The tissues of the 

 luesophyll of the leaves are overrun with hyaline, branched, septate 

 hyphae 4 microns in width. On the upper surface of the leaves are 

 produced black perithecia which are not visible to the naked eye- 

 The perithecia are less abundant on the under surface of the leaves ; 

 they are closely associated with the internal mycelium, and when 

 viewed under a lens appear as small black dots ; they bear asci with- 

 out paraphyses, each ascus containing eight ascospores. 



The fungus belongs to the genus Laestadia, and in its characters 

 is sufficiently distinct from any other species of Laestadia to be 

 designated a new species. It has been named L. Palaqidi, n. sp. • 



Other species of the genus Laestadia which have been recorded in 

 the East are : — L. Theae, Rac, described on tea in Java, which the 

 new species resembles somewhat in the characters of perithecia and 

 asci, but from which it differs markedly in the nature of the spots and 

 mode of arrangement of the perithecia ; L. Camdleae, Cooke, described 

 on CamUlea Then in Johore ; L. Oxalidis, Sacc, on Oxalis corniculata in 

 Ceylon; L. Pertu^a, Sacc.,- on Dioscorea tomentosa m Ceylon; and 

 L. Caesalpiniae Pat. on species of Caesalpi?ua. in Java. 



The best known case of parasitism of the genus is that L. Bid- 

 wellii on the Vine in the United States of America and in France ; this 

 fimgus which causes the ** black rot " is the most dreaded fungus- 

 parasite on the Vine in the United States. 



Spread of the Disease. 



It is npt improbable , that the' rapid spread of the disease is 

 brought about by the presence of a pj^cnidial form of the nature of a 

 Phoma. A small pycnidial fofm has appeared on the spots pre- 

 viously toUhe development of the perithecia and has been identified 

 as a Phoma ; and a careful examination of material is being made for 

 the purpose of demonstrating the connexion between this and the 

 ascigerous fungus. 



