134 Biffen . — On the Biology of Bulgaria poly morpha. 
EXPLANATION OF FIGURES IN PLATE VII. 
Illustrating Mr. Biffen’s paper on Bulgaria. 
Fig. i. Longitudinal section through a ripe ascophore to show the ‘ veins.’ 
Fig. 2. A culture of the Fungus on oak-wood between three or four weeks old. 
The light patches are the earliest visible stages of the developing ascophores. 
x i. 
Fig. 3. Pitted walls of oak-wood seen in surface view, showing various stages 
of delignification. Near the centre of the figure the pits have only recently been 
attacked, as shown by the narrow delignified zone surrounding them. These 
zones extend until they meet, as in the top left-hand corner, and ultimately the 
whole wall becomes delignified. x 375. 
Fig. 4. Transverse section of oak-wood to show the earliest stages in its decom- 
position. The delignified lens-shaped patches are to be associated with the position 
of ‘ pit-threads.’ x 600. 
P'ig. 5. A similar preparation to show the dissolution of the middle lamella. 
The central cell shows the middle lamella in its normal condition on the right- 
hand side, while almost complete dissolution is shown in the right-hand bottom 
corner. The solution of the ‘ intercellular protoplasm ’ has just become visible, 
x 600. 
Fig. 6. A longitudinal section of an ascophore about 2 mm. high, in which the 
conceptacles are developing rapidly to form the main mass of the ascophore. The 
dark portions indicate the position of carbonized hyphae. 
Fig. 7. A portion of a similar section in detail. The hyphae have swollen out 
in a balloon-shaped fashion and acquired slightly thickened walls, x 375. 
Fig. 8. Transverse section of an adult ascophore for comparison with Fig. 1. 
The net-like arrangement of the ‘ veins ’ is due to the number of carbonized con- 
ceptacle walls pressed together, x 25. 
