178 
MILDEWS, RUSTS AND SMUTS 
The aecidium condition occurs in two rows, on one row 
each side of the midrib, on the under surface of the leaves 
of the silver fir —Abies pectinata, also on Abies nordmannia, 
A. nobilis, A. ma^nifwa, A. concolor, A. balsamea, A. 
fraseri, A. cilicia, A. cephalonica, A.pictita,A. pinsapa, 
and A. vietchii. 
The teleutospore stage grows on the shoots of the cow¬ 
berry —Vaccinium vitis-idaea in this country, it occurs on 
Vaccinium myrtillus and on V. chandleri in the United 
States. Infected branches of the cowberry grow perfectly 
erect, and the entire plant is taller than healthy ones, and 
the leaves are stunted. The stem becomes much swollen 
and spongy, rosy, then brown, finally blackish. The 
teleutospores are produced in the epidermal cells of the 
swollen portion. 
The silver fir suffers most in this country, but diseased 
specimens of A. nordmannia have also been sent to Kew 
from Wales. 
ROSTRUPIA, Lagerh. 
Uredospores. Sori flattened ; spores produced singly on 
short, colourless pedicels. 
Teleutospores. Sori flattened; spores 2, many-septate, 
forming a single row of superposed cells, each cell having 
one germ-pore, coloured, enclosed in a pseudoperidium 
formed of closely compacted, .coloured hyphae. 
Distinguished from allied genera by the presence of a 
pseudoperidium composed of closely compacted, coloured 
hyphae, surrounding the teleutospore sorus. Aecidia are 
at present unknown. 
Rostrupia elymi, Lagerh. 
Uredospores. Sori on the upper surface of the leaf, 
solitary or grouped in lines and often running into each 
other, small, pale, paraphyses absent; spores ovate, minutely 
echinulate, pale brown, usually 8 germ-pores. 
Teleutospores. Sori small, often elongated, not very 
conspicuous ; spores generally 2—3-septate, cylindrical 
or somewhat spindle-shaped or club-shaped, very slightly 
or not at all constricted at the septa, tip blunt, base nar¬ 
rowed, smooth, pale brown, tip thickened and darker, 
pedicel very short, dark brown, persistent, surrounded by a 
pseudoperidium formed of closely compacted brown hy¬ 
phae, which often rise up from the base, between the spores, 
as a thin wall, thus dividing the sorus into 2—3 compart¬ 
ments. 
