350 MELAMPSORA 
Uredospores. Sori hypophyllous, minute, 4 mm., somewhat 
pulvinate, pulverulent, spots obsolete; spores oval, oblong or 
obovate, rarely round, 15—22 x 10—15y; epispore about 2 
thick, covered with stout spines; paraphyses distributed through- 
out the sorus, elongated-clavate rather than capitate, 40—45 x 
8—17 p, with a thick wall (3—9 ,). 
Teleutospores. Sori hypophyllous, minute, $—1 mm. diam., 
covered by the epidermis, dark-brown; spores prismatic, rounded 
at both ends, 40—60 x 7—12,y; epispore thin (1—2), not 
thickened above, with a scarcely evident germ-pore. 
Ceomata on Laria europaea; uredo- and teleutospores on 
Populus alba, P. tremula, rarely P. balsamifera, September, 
October. 
The description is after Klebahn. The teleutospores germinate after 
a winter’s rest. Though Plowright records that he could obtain no result 
“by placing the germinating teleutospores of M. tremulae on young larch 
trees” (2c. p. 241), the truth of the hetercecism has been abundantly 
demonstrated by Hartig, Klebahn and Fischer. Plowright mentions that’ 
Prof. Trail had found these two forms growing in company near Aberdeen ; 
and the meaning of his failure is simply that he was using one of the 
other Melampsorae that grow on P. tremula. It has been suggested, but 
not proved, that Jf pinitorqua is itself only a biological race, and there 
are also M@. Magnusiana (Klebahnz), and M. Rostrupit which may come 
under the same category; see p. 353. 
(2) Metampsora PINITORQUA Rostr. 
Cacoma pinitorquum A. Braun, in Monatsb. Berl. Akad. 1863, p. 624. 
Melampsora pinitorgua Rostr. Tidsskr. f. Skovbrug, 1889, xii. 177. 
Fischer, Ured. Schweiz, p. 499. Yorkshire Fungus Flora, p. 183. 
Massee, Text-book of Fungi, f. 22, 98; Text-book of Plant 
Diseases, p, 235, f. 60; Dis. Cultiv. Plants, p. 325, f. 98. 
Aicidiospores. Czomata erumpent through the cortex of 
young shoots, solitary, linear, reaching 20 x 3mm., reddish- 
orange ; spores roundish or oval, pale reddish-yellow, 14—20 x 
13—17 u, or oblong, 22 x 104; epispore about 2 thick, deli- 
cately verruculose. 
Uredospores. Sori hypophyllous, on spots which show yellow 
chiefly on the upper side, solitary or in groups, often scattered 
over the whole surface, scarcely $ mm. wide, pulvinate; spores 
