246 Dawson.—On the Biology 
It is usually cited as another example of the type of life- 
history exemplified by Xylaria , or as a member of the group 
Xylarieae, forming characteristic stromata, with one definite 
type of conidia, followed later by perithecia with asci and 
ascospores 1 . 
A rough examination of the Fungus was sufficient to show 
that, in common with other members of its group, it offers 
many very interesting points for investigation ; accordingly, 
at the suggestion of Professor Marshall Ward, to whom my 
thanks are due for many suggestions throughout the work, 
I undertook a somewhat detailed study of the species Poronia 
punctata , in November, 1899. For the material on which 
the work was carried out I am indebted to Dr. Plowright, 
who collected it in the neighbourhood of King’s Lynn, 
Norfolk. 
Life-History. 
Poronia punctata is an Ascomycetous Fungus, growing 
upon horse-dung, and characterized by its pegtop-shaped 
stromata with a whitish disk-like upper surface, mounted 
upon an unbranched stalk, rarely more than 1 cm. in height, 
and either standing erect above the surface of the substratum, 
or, as frequently happens, embedded within the substratum, 
so that only the expanded disk-shaped head is exposed to 
view (Plate XIV, Figs. 1 and 2). 
In the earlier stages of development the upper parts of 
the stromata are covered with a greyish white powder, the 
conidia ; these are followed by black spots, scattered over the 
flat surface of the disk. These spots are the ostioles of the 
perithecia, which are embedded in the uppermost layers of 
the stromata, an arrangement which led Berkeley 2 to draw 
attention to the superficial resemblance of these stromata 
to the antheridiophores of Marchantia . When the asci are 
1 E.g. Fuisting, Bot. Ztg., 1867-68; Cornu, Ann. d.Sci. Nat. (Bot.), ser. vi, 1876; 
De Bary, Comp. Morph. Fungi' and Mycet., p. 244; Zopf, Die Pilze, 1890; Von 
Tavel, Vergl. Morph, d. Pilze, p. 92. 
2 Berkeley, Introd. to Crypt. Bot., 1857, p. 441. 
