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A NEW SPECIES OF MONOCHAETIA. 



(With Plate VIII.) 



By Malcolm Wilson, D.Sc, F.R.S.E., F.L.S. 



Reader in Mycology, University of Edinburgh 



and 



F. C. Ford-Robertson, B.Sc. 



Indian Forest Sercice. 



The fungus forming the subject of this note was found on the 

 dead leaves of Cryptomeria japonica D. Don, which were still 

 attached to the cast shoots. It was collected in November, 192 1, 

 at Raith, Fife, on shoots which had e\-idently lain on the ground 

 for some months. Detailed investigation of the material was 

 not commenced until Januan% 1923. 



The fructifications, which are isolated and found sparingly 

 on all sides of the leaf, are dull black and smooth, in shape oval 

 to eUiptical and up to i x 'yf, mm. in size when mature. They 

 may project as much as -3 mm. above the surface of the leaf; 

 young fructifications are more roimded and project to a less 

 degree. On examination the matm^e fructification appears to 

 consist almost entirely of a spherical mass of dark-coloured 

 spores and is encircled by the ruptured epidermis, an indication 

 that it was in the early stages embedded in the tissue of the leaf. 

 Sections confirm this, and the fructification, seen just below the 

 epidermis, is globose, consisting of a reddish-broN\Ti wall about 

 20 /i in thickness, made up of intervvoven h\-phae, which on the 

 outer 5iu-face gradually pass off into the tissue of the leaf (fig. i). 

 The inner siu-face of the wall is sharplv dehmited by the hyahne 

 sporophores which project from it thickly and bear the elongated 

 spores. As development proceeds the epidermis and wall of 

 the fructification immediately below it rupture and the free 

 edges of both form an aperture which gradually widens to 

 expose the spore-bearing layer. The fructification, immediately 

 after dehiscence, is flask-shaped and, in consequence, the sporo- 

 phores near the opening are still directed inwards (fig. 2). As 

 the aperture %\-idens this appearance is lost, the spore-bearing 

 layer becoming finally almost flat. Mucilage is e\"idently pro- 

 duced, even before rupture, by degeneration of the wall and 

 sporophores, and dehiscence is probably brought about by 

 absorption of water and consequent swelling. The mucilage 

 flows out over the surface as a cushion-hke layer and carries out 

 the spores embedded in it; bv the time that the fructification 

 is widely of)en the majority of the spores are found on the surface 

 of the leaf in the dark-coloiu^ed mass pre\'iously referred to. 



M.S. 13 



