258 Dazvson .— On the Biology 
The conidium-forming hyphae are divided into very small cells 
by numerous septa, and they tend to break down into these 
component cells, and as a result this layer of hyphae falls away 
during the formation of perithecia (Figs. 31, 32). This pheno¬ 
menon was pointed out by Tulasne, Brefeld 1 y and Von Tavel 2 . 
If sections of stromata of Poronia of various ages be treated 
with strong potash at 160° C. and stained with iodine and 
sulphuric acid, in the manner described by Wisselingh 3 , it 
is seen that the walls of the hyphae all contain chitin, with 
the possible exception of the outermost rind-like layer, which 
retains its original brown colouration. 
After a study of the internal anatomy of Poronia punctata , 
one is perhaps most struck by its many points of resemblance 
with Polystigma rubrum and P. fulvum ; this is of course 
especially noticeable in the form of the archicarp, which in 
Polystigma consists of ‘a long coiled row of many cells,’ 
one extremity of which projects above the surface as a 
trichogyne. The coil appears to divide up into portions, 
which, after distribution over the hypothecium, branch to 
form the ascogenous hyphae. The marked point of difference 
between the two genera is the formation in Poly stigma of 
spermogonia with spermatia, whilst in Poronia degeneration or 
development, as the case may be, has resulted in the entire 
absence of these bodies. In Polystigma , however, the union 
of spermatia with the trichogyne has not yet been observed. 
It should be pointed out in this connexion, that although, 
in Poronia , perithecia with ripe asci have been formed on 
stromata grown in captivity, yet the number of perithecia 
developed was smaller than in those stromata which had 
reached the stage of immature ascospores before the material 
was brought into the laboratory. Also, whilst the former 
took at least one month to form asci, in the latter specimens 
the spores ripened in a few days. We are, of course, unable 
to say how long is required for the earlier stages in the 
1 See Brefeld, 1 . c., Heft x, p. 261., 
2 Yon Tavel, Vergleichende Morphologie der Pilze, p. 92. Jena,, 1892. 
2 Wisselingh, Pringsh. Jahrb., 1898. 
