COLEOSPORIUM. 



375 



The aecidia are produced amongst the pycnidia on needles 

 two or three years old ; they have long white peridia and 

 are known as Pcridermium ohlonfjisporinm Fuck. The aecidio- 

 spores are yellow when mature, and originate in chains, which 

 in the earlier stages of development consist of intermediate 

 cells and spores, but the former gradually disappear (Fig 208). 

 The spores have an average length of 30-5m and breadth of 



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V\c,. 208. — Pcridii-mmra /)in! (Colioyioriiim xni'iionin). Portion of an aecidiiim 

 with basidia (6) giving off spores aud intermediate cells (d)\ outside the 

 lieridiuni (p) other busidia {<) with club-shaped ends force up tliu epidermis; 

 <', the thick mj'celiuni in the leaf-parenchyma. (After R. Hartig.) 



20/x; in form they are generally longish-oval, few being round; 

 the spore-coat is moderately thick. Aecidiospores are capable 

 of immediate germination, and ]»roduce f//-(r^-patches on Smieno 

 by June. 



The uredospores have an average length of 28'oai, and 

 breadth Io-q/a; they are generally oblong, with a moderately 

 thick coat Ijeset with spiny warts. 



