igo Transactions British Mycological Society. 



The spores (fig. 3) are spindle-shaped, constantly five-celled, 

 slightly constricted at the septa, the three central cells (6, c, d) 

 with smooth, chocolate-brown walls of even thickness and pale 

 yellow granular contents; the central cell (c) is invariably the 

 darkest. The terminal cells {a, e) are hyaline, occasionally sub- 

 hyaline, with scanty colourless contents and often with a single, 

 rather large oil drop. The proximal cell [a), which possesses a 

 wall of marked thickness, is separated from the sporophore by 

 a cross wall; the sporophore itself is hyaline, 4-20 /u, long, 1-2 /x 

 thick and is often divided into two or three cells. The distal 

 cell [e) is hyaline, thin-walled, with scanty contents, occasion- 

 ally with an oil drop and is prolonged into a tapering seta which 

 is generally bent or curved, 20-32 /x long and barely i/x thick 

 at the base. The process of spore development has not been 

 elucidated but the structures shown at / and g in fig. 3 appear 

 to be early stages. 



The mycelium in the leaf consists of very delicate hyaline 

 hyphae which spread in all directions through the tissues. At 

 maturity the fructifications appear very shrunken and are not 

 easily distinguished in the dead leaf. Although at the time of 

 examination the material had been kept for fourteen months in 

 a dry condition in the laboratory, the spores released from the 

 soaked material were found in a germinating condition. Ger- 

 mination, which may take place within twenty-four hours, is 

 invariably preceded by a change in colour and cell contents. 

 The brown cells, which alone produce germ tubes, become paler 

 in colour and conspicuous oil drops appear in the contents, 

 although they are rarely or never seen in the resting spore. 



On germination the outer layer of the wall is ruptured and the 

 inner colourless layer emerges to form a germ tube of variable 

 thickness usually about 2 ju in diameter (fig. 4) . Near the point of 

 emergence the protoplasm becomes paler in colour and in the 

 germ tube is completely hyaline ; the oil drops generally flow out 

 as development proceeds. Whilst still very short the germ tube 

 may bifurcate before any cross septa are formed [a, fig. 4) . 



In most cases germ tubes are only produced from the dark- 

 coloured cells adjoining the central one, each of which may 

 produce two. Most frequently two germ tubes are produced 

 from the whole spore, each of the cells contributing; the maxi- 

 mum number, four, is rarely found but three is fairly common. 

 The central cell has only once been seen to germinate and the 

 terminal hyaline cells apparently never do so. During germina- 

 tion the setae gradually disintegrate. Germination was obtained 

 as readily in a 2 per cent, solution of glucose as in water. 



Spores placed on agar media readily produce an abundant 

 mycelium. Different media were employed and gave growths of 



