438 Williamson .— The Origin of ‘ Golden ’ Oak. 
end cell-walls, with occasional branches passing to the wood parenchyma in 
the vicinity. The passage through the pits in radial section is illustrated in 
Text-fig. 2. Finally the tracheides, wood-vessels, and fibres are entered, 
and here the hyphae appear to travel longitudinally, in the main, though 
fairly numerous lateral branches into surrounding cells do occur (PI. X, 
Fig. 2). 
The hyphae, as a rule, are septate and branched, with occasionally 
a swollen irregular appearance with frequent septation, such as was found 
when the fungus was growing on synthetic agar at 25 0 C. The frequent 
presence of hyaline spores of all sizes was noted in the medullary ray cells 
and in the wood parenchyma and vessels, both in the older infections and in 
the original ‘golden’ oak. Comparisons of the dimensions of these hyaline 
spores and those of E . catenulata showed the same range of variation, 
though the smaller sizes were perhaps more abundant in the wood than in 
cultures. Text-fig. 3 shows hyaline spores in medullary ray cells and wood 
parenchyma in tangential sections of oak. 
Conidia also occur frequently in infected oak. Text-fig. 4 shows the 
lumen of a vessel of the original 4 golden ’ oak with conidia scattered and in 
