Gym nospora iigiu ui. 235 



spore mycelium, while the teleutospores only require two or three 

 weeks in which to perfect the mycelium bearing the ascidiospores. 



The germ-tubes of the jecidiospores will not enter old leaves, but 

 only those produced the same year the experiment is made ; or, if 

 they do enter the former, the mycelium will not penetrate into the 

 perennial tissues of the host-plant. Hence it is useless attempting to 

 infect a bush which has recently been transplanted ; but there is no 

 difficulty with an established plant, which has thrown out a number of 

 young leaves. Once established in the juniper, the mycelium lives in 

 a vigorous condition, annually producing teleutospores for many years. 



Gymnosporangium juniperinum. (Linn.) 



JEcidiospot-es — Pseudoperidia on orange or red, roundish spots, 

 cylindrical, curved, yellowish brown, 8-10 mm. long, open 

 above, fimbriate. Spores subglobose, brown, finely verrucose, 

 21-28 X 19-24JU,. 



Teleutospores — Mycelium perennial. Spore-masses at first dark 

 brown, then orange, soft, gelatinous, subglobose. Spores of 

 two kinds : (i) fusiform, brown, with thick epispore, 75 X 27/x ; 

 (2) yellow, with thinner epispore, about 66xr7/u,, having 

 ■six germ-pores. 



Synonyms. 



Winter, loc. a'f., p. 234. 



Ti'emella juniperina. Linn., "Sp. Plant.," p. 1625. 



Gymnospoj-angium juniperi, Link. Berk., " Eng. Flor.," vol. v. 

 p. 361 ; "Outl.," t. ii. fig. 2. Cooke, " Hdbk.," p. 509 ; "Micro. 

 Fungi," 4th edit., p. 214. 



y£ddium corfwtinn, Pers. Berk., "Eng. Flor.," vol. v. p. 373. 

 Johnst, " Flor. Berw.," vol. ii. p. 207. Sow., t. 319. Grev., t. 180 ; 

 "Flor. Edin.," p. 447. 



Rcestelia cornuta, Tul. Cooke, "Hdbk.," p. 534; "Micro. 

 Fungi," 4th edit., p. 190, t. ii. figs. 18, 19. 



Exsiccafi. 

 Cooke i. 1 ; ii. 441. Vize, "Micro. Fungi Brit," 54. 



^Ecidiospores on Fyrus auciiparia, July to October. 

 Teleutospores on Juniperus communis, ALay to June. 



Biology. — The teleutospores do not generally appear until May. 

 They readily produce promycelial spores in water, which, when applied 



