ON THE LIFE-HISTORY OF HEMILEIA VASTATRIX. 299 
Researches on the Life-history of Hemileia vastatrix, the 
Fungus,of the “Coffee-leaf Disease.” By H. MARSHALL 
Wary, B.A., Fellow of Owens College, Manchester, late on 
special duty as Cryptogamist to the Government of Ceylon. 
(Communicated by W. T. Tuisexton Dyer, F.R.S., F.L.S.) 
[Read June 1, 1882.] 
Ix a recent paper * I have systematically brought together the 
main facts concerning the morphology of Hemileia vastatrix 
discovered up to May 1881, and have shown that in essential 
points of structure and development this remarkable fungus 
presents features sufficiently numerous and important to suggest 
its alliance with known Uredinec. During the progress of an 
investigation occupying nearly two years, I have accumulated 
numerous observations of no less weight, proving that, in its 
physiological and pathological peculiarities, Hemileia also re- 
minds us of the behaviour of the Uredine fungit. Since many 
of the experiments upon which these conclusions are based are 
of an exhaustive nature, while some few are more or less novel 
in character, I propose to bring them forward in detail as further 
evidence in support of the now widely accepted view on the rela- 
tions of parasitic fungi and their hosts generally, and of the 
Uredines in particular. 
Those who have followed the more recent history of the so- 
called ** Coffee-leaf disease " of Ceylon will recognize that several 
of the details entered into below are not new. 1 haverestated, in 
à more systematie form, one or two facts already published in 
periodical reports f, apart from matters of comparatively local 
interest, in order to aid in the comprehension of their important 
bearing upon the subject under discussion. 
For the sake of completeness, moreover, as well as because 
Such a résumé possesses considerable advantages for and by 
itself, I shall enter upon several points in the general theory of 
parasitism, so ably and firmly established of late years by 
De Bary $ and fellow workers, and upon which my researches 
* Quart. Journ. Microse. Sci., January 1882. 
t The details are published in three Reports to the Ceylon Government, 
1880-81. 
i Vide Esp., “Third Report to Ceylon Government,” Sessional Paper xvii. 
1881. 
$ Cf. De Bary, ‘Die Brandpilze,’ 1853, part iii, and Frank, ‘ Krankheiten 
d. Pflanzen,’ p. 447 &c., and lit. quoted. 
