162 
Fig. 7. 
8. 
9. 
10. 
Fig. 11. 
12. 
13. 
Fig. 14. 
15. 
16. 
17. 
ON THE BIOLOGY OF COLLYBIA VELUTIPES. 
Section of a lamella with cystidia. 
Early stage in the development of a sporophore from the rudimentary 
sclerotium. The large, pigment-containing hairs develop early and 
often serve to distinguish the sporophore from the sclerotium. 
A longitudinal section of a sporophore about 2 mm. high, in which a 
cortical layer has been differentiated. The subhymenium is not 
differentiated yet. 
An early stage in the development of the subhymenium, also showing 
the large hairs of the recurved margin pointing towards the stipes, 
but not joined to it. The sporophore was about 5 mm. high. From 
a microtome section stained in Delafield’s hematoxylin. 
PLATE 3 
Germinating oidia, penetrating through the pitted wall of a tracheid ; 
the wood infected a week previously. 
Mycelium within the wood elements breaking up into oidia-chains; 
from the same preparation as fig. 11. 
Radial section of a block of ZEseulus-wood, infected four weeks 
previously. The irregular holes in the walls show where the hyphe 
have pierced the walls and then further corroded them. The 
rosettes of crystals are formed of bundles of calcium oxalate raphides. 
PLATE 4. 
Hyphx within the wood elements become shortly septate to form a 
rudimentary rhizomorph strand, 
Transverse section of ZEseulus-wood to show various degrees in the 
destruction of the thickening-layers, from slightly corroded portions, 
appearing as pits, to almost complete solution. 
Longitudinal radial section of ZEsculus-wood with the walls of the 
tracheids and medullary rays grooved and pierced by the action of 
the hyphze ; from a preparation stained in Bismarck brown. 
Wood treated as described with caustic potash and stained with iodine 
solution and sulphuric acid. The lignified middle lamella is yellow, 
the corroded thickening-layers, blue, and the chitin-walls of the 
hyphe, pink. 
