[409] 



^be Hacomijcetc^.'' 



THE fourth volume of this comprehensive work on British 

 Fungi is devoted to the Ascomycetes, and with the kind 

 permission of Messrs. George Bell and Sons, we purpose 

 making one or two short extracts. 



The very large number of species of fungi included in the 

 group known as the Ascomycetes are characterised by having their 

 spores produced in asci^ or mother-cells. In the great majority of 

 species the asci are numerous, closely packed side by side, and 

 form the disc or hymenium^ seated on and protected by a structure 

 called the ascophore^ which is either parenchymatous — that is, com- 

 posed of a mass of more or less polygonal cells, united to form a 

 tissue — or consists of densely interwoven septate hyphae. 



The Ascomycetes are divided into the following families, viz. : 

 Gymnoascaceae, Hysteriaceae, Discomycetes, Pyrenomycetes, and 

 Tuberaceae. 



For our first plate in illustration of this work we have chosen 

 that representing the second family : — 



HYSTERiACEiE (Plate XXI.). 



Ascopores erumpent, innate, or superficial ; horizontally ellip- 

 tical or linear, or vertical and laterally compressed ; texture carbon- 

 aceous or membranaceous ; dehiscing by a narrow slit running the 

 entire length of the ascophore, black or blackish- brown ; asci 4—8 

 spored ; spores hyaline or coloured, continuous or septate ; para- 

 physes usually present. The species are all minute, and mostly 

 gregarious ; all are saprophytes, growing on old wood, bark, and 

 also on dry leaves. 



Explanation of PI. XXL, showing Figures illustrating the 

 Hyste7'iacece, etc. — Fig. i, Lophium mytillinum^ Fries, a group of 

 plants, nat. size. — Fig. 2, one ascophore ; slightly magnified. — 

 Fig. 3, ascus and paraphysis ; highly magnified. — Fig. 4, spores of 



* British Fungus Flora : A Classified Text-Book of Mycology. By 

 George Massee, author of '' Plant Life," " The Plant World," etc. Vol. IV. 

 Cr. 8vo, pp. viii. — 522. (London: Geo. Bell & Sons. 1895.) Price 7/6. 

 We thank the publishers for the loan of the electros, from which the accom- 

 panying plates are printed. 



International Journal of Microscopy and Natural Science. 



Third Series. Vol. V. dd 



