ОЕ А REMARKABLE UREDINE. 143 
carefully protected from exposure to normal attack, although there was little need for 
this precaution, as the parasite does not occur in Simla, keeping well to the deep valleys 
below. Upon these leaves a few teleutospores were placed, and to my great pleasure 
two typical æcidial patches were produced, which, after running a normal course, went 
on to the formation of teleutospores in the cups which had originally borne гесійіоврогев, 
thus eompleting the whole cycle of development. 
Owing to the unfortunate mistake I made in confusing Jasminum officinale with 
J. grandiflorum, Т had no further opportunity of confirming this single experiment by 
others, the season for experiment having passed by. During the following year (1888) I 
was absent from India, and the investigation had to lie over until my return. Since then 
І have succeeded in numerous instances in producing ecidial patches with sporidia, and 
this relationship is established beyond all doubt. The mistake, however, which I 
made in confusing hosts is not without interest, showing how extremely selective some 
species of the Uredines are іп the choice of their hosts. J. officinale is very nearly 
related to J. grandiflorum*, and yet numerous and prolonged efforts to produce the 
ZEcidiwm on it failed entirely. I may also mention that another species of Jasmine, 
J. humile, L. +, harbours an entirely different cidiwm. So that the three common 
species of Jasmine in this neighbourhood are sharply distinguishable from one another 
as hosts of the Отейтез. А knowledge of this fact, it is conceivable, might be of 
use to systematists in deciding the specificity of a disputed plant. Should the question 
arise whether our common Simla J. officinale is merely a variety of J. grandiflorum, the 
fact that a well-defined parasite will readily select the one to grow upon, while it will 
have nothing to say to the other, would possibly influence a decision. 
I had personally met with the parasite only at Sairi, but a servant of mine, living in 
a low-lying valley near Simla, but in a different direction, seeing me interested in this 
“ blight,” brought me several shoots collected near his village, as densely attacked as 
any I had seen at Sairi. The fungus appears therefore to be common in the deep valleys 
about Simla, $, e. at elevations of about 4000 to 5000 feet, though it never comes up to 
the elevation of Simla. I have not been able to ascertain the extent of its distribution 
downwards towards the plains; but at one village at the foot of the hills, where this 
species of Jasmine is abundant, I saw no trace of it. It would thus appear, on the 
insuffieient data available, that in vertical distribution this fungus is remarkably 
limited. 
Transverse sections through affected portions of the stem show that mycelial inva- 
sion is mainly limited to the cortical parenchyma; but at a few points some hyphx 
may be seen entering the margin of the central pith by way of the medullary rays 
(РІ. Г. fig. 2). 
The main seat of invasion is therefore the cortical parenchyma, and this tissue, when 
invaded, is greatly hypertrophied. In the transverse section of an affected stem about 
3:95 millim. in diameter, I noted that whilst the depth of the normal layer of cortical 
* See descriptions in Sir J. D. Hooker's * Flora of British India,’ iii. p. 603. 
+ ‘Journal of the Asiatic Society of Bengal,’ vol. lvi. pt. п. р. 363 (1888). 
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