111 
time when it first appears. All known species of ISCONMMMARIN 
are parasites, forming blisters or galls on the leav es and bra 
of the host plant ; the flowers and fruit are 
Species belonging to the following genera are known to serve as 
host plants :—-Rhododendron, Vaccinium, Andromeda, Cassandra, 
EN ADAE Ledum, Saifraga, Laurus, Si Voc d 'ena- 
therum, and Bromus. The above list of genera belonging to 
diy separated orders of AD suggests T Possit ot some 
ally of the tea plant also serving as a host for the * blister blight," 
is but little hope of eradieating the disease until suc 
The following is a diagnosis of the species :— 
Exobasidium vexans, Mussee. 
H. ymenophora innata, effusa, forma varia, vulgo orbicularia vel 
oblonga, in foliis infestatis bullas supra concavas infra convexas 
4-12 mm. diam. interdum confluentesformantia. Hymeniumleve, 
siccitate rimosum, initio pallidum, dein state albo-pruinosum. 
Basidia cylindracea 30-35 x 5-6 p, actis sterigmata 
aculeata, 3 x Op. Spore grips ux, hyaline, 
glabrz, sepe gasiti, 2 x 3p. Conidia taa hvala 
l-septata, ad septum leviter constricta, 14-16 x 5-6 y. 
On living leaves and branches of Camellia Thea, Ass 
Fig. 6, Leaf of tea plant, with blisters formed by blister blight 
(Benbesidines vexans); nat. size. Fig. 7, Section through a 
blister; x 100. Fig. 8, Portion of hymenium of same, showing 
numerous conidia, v, and basidia, b, bearing two spores each ; 
x 400. Fig.9, Free spores; x 400. Fig. 10, Conidia ; x 400 
THREAD BLIGHT, 
(Stilbum nanum, Massee). 
This very remarkable d Ming: agreeing technically with 
the genus Stilbum in the structure of the conidiophore, differs 
very materially in the presence of it etabaesteyy branched, sterile 
stroma composed of densely interwoven, slender, oped septate, 
vaguely branched ae 2-3 p in diameter, combin 
thin, white membrane, which is inseparable from the berk or leaf 
on which it UNS. This sterile felted mycelium often forms 
branches, and then breaks up into irregularly-branched slender 
strands, many of which are not thicker than thread, hence the 
planter's name “thread blight.’ "The delicate white strands of 
mycelium run alon ng the surface of the bark to the tips of the 
young shoots, b irregularly ; thence they 
not infrequ iently pass “on to the leaves, where they form a yet 
more delicate, irregularly branched pattern. Microscopic examina- 
tion of a diseased branch shows that the slender mycelium is at 
first most abundant in the cambium ae and extends to the young 
wood, the vessels of which soon become choked with a dense weft 
of myc o A slight browning of the tissues indicates m 
progress of the mycelium. This rnal mycelium m passes throu 
the * substance of the bark, and dum audi to the superficial stands 
