'•sfcK 



MEMOIRS. 



On the Morphology of Hemileia vastatrix, Berk, and Br. 

 {the Fungus of the Coffee Disease of Ceylon). By H. 

 Marshall Ward, B.A., on special duty as Cryptogamist to 

 the Ceylon Government. (With Plates I, II, III.) 



During the past twelve months the progress of my investiga- 

 tions into the-life history of Hemileia vastatrix, the fungus so 

 prominent in the so-called " coffee-leaf disease " of Ceylon, has 

 resulted in the accumulation of a series of facts concerning its 

 structure and development which have been hitherto undis- 

 covered, or, in some cases, misunderstood. Sufficient material 

 being now at hand to throw light upon the morphology of this 

 remarkable parasite, I purpose bringing together shortly the main 

 points whicli have been established.^ 



Since it is not intended to enter upon any speculations, and 

 none of the numerous physiological and pathological phenomena 

 of '^ leaf disease " can be introduced here, it appears unnecessary 

 to discuss at length the previous pubhcations on the subject of 

 " coffee-leaf disease.''^- In so shortly referring to them no in- 

 attention is imphed, but it will be impossible to clear up points 

 of difference without numerous figures in addition to those 

 hereto annexed. Nor is it necessary to enlarge upon the history, 

 so far known, of this serious pest to one of our most important 

 cultivations. I shall therefore proceed at once to the immediate 

 object of the present paper. 



^ Mr. Marshall Ward has reviewed the whole course of his investiga- 

 tions, especially in relation to the economic aspect of the subject, and the 

 possibility of remedial measures, in a final report to the Ceylon Government 

 (Colom'oo, Sessional Paper XVII, 1881).— [Ed. 'Q. J. M. S.'j 



- They are chiefly — Ahbuy, ' Journ. Linn. Soc.,' Dec, 1878 ; Morris, 

 ' Journ. Linn. Soc.,' March, ISSO ; and a valuable summary of the v^hole 

 question up to 1880, by W. T. Thiselton Di/er, ' Quart. Journ. of Mic. Sci.,' 

 April, 1880. Smaller papers by Cooke, Berkeley, Thwaites and Morris, are 

 referred to in these. 



VOL, XXII. NEW SER. A 



