LIFE-HISTORY OF HEMILEIA VASTATRIX. 335 
Whether any natural check to the further progress of this pest 
will arise is at present problematical, much as it may be desired 
from an economical point of view. 
It may be remarked that, although careful trials have been 
repeatediy made, I have utterly failed to infeet either the coffee- 
leaf or any other plant with the small “sporidia” produced 
by the germination of the teleutospore of Hemileia; no evidence 
exists for doubting that the reproduction of the fungus on coffee- 
estates takes place wholly by meaus of the innumerable uredo- 
spores, as described. 
Several Zcidia (notably those on Emilia, Tabernemontana, 
and Pavetta) have been experimented with, to observe whether 
their spores can be made to infect coffee. In no case has any 
positive result been obtained; and the obverse is also true—the 
teleutospores of Hemeleia did not infect the plants named. I 
hope that further trials wil be made, however, with Pavetta 
indica and P. angustifolia: two Æcidia (As. flavidum and 
4E. Pavette) have been described * on these hosts; and it is 
remarkable that the genus Pavetta stands somewhat closely 
allied to Coffea. As to the original source of this fungus, there 
can be no reasonable doubt of its antiquity T. "Whether Hemi- 
leia vastatrix is more than a form of H. Canthii, moreover, must 
be considered at present undecided. 
A List of published Specigs of Cape Orchidee. 
By Harry BoLus, F.L.S.£ 
[Read May 4, 1882.] 
Tuz literature of Cape Orchidology is so scattered that the 
Student is beset with diffieulties at the outset in the attempt to 
ascertain what has been already described. Since Liudley's 
* Genera and Species of Orchidaceous Plants? (1830-10), there 
has been no attempt at a general list. Many subsequent addi- 
tions have been made, chiefly to the flora of the Eastern Region ; 
and there are stil many unpublished species from Kaffraria, 
* Messrs. Berkeley and Broome, in Journ. Linn. Soc., Bot. vol. xiv. 
U t As first suggested, I believe, by Mr. Thiselton Dyer. 
1 See paper “ Notes on some Cape Orchids,” and footnote an/eà, p. 233. 
LINN. JOURN.— BOTANY, VOL. XIX. 2r 
