132 BROOKLYN BOTANIC GARDEN MEMOIRS 
cially abundant along some of the medullary rays. It is not evenly 
distributed. The hyphae seem to travel in fascicles and they are 
everywhere intercellular. Sections of the wood show that there are 
strands of parenchyma that, from appearances, would seem to be 
burrowing through the wood, thrusting the tracheids aside as though 
endowed with great power. These same parenchyma strands are 
also found in the cortex. They run in almost every direction. Hyphae 
are always associated with them. Tracheids in infected areas of the 
wood are considerably modified. The walls are thinner, the cells are 
prismatic and in many cases have failed to develop bordered pits. 
The walls of such cells frequently appear to be broken down or 
crushed in and partially disorganized. It may very well be that the 
fungus has some power to disorganize lignified cell walls. Wherever 
hyphae occupy the lumen of a cell it is likely to have been the result 
of such mass action. There is no boring through the walls nor entering 
tracheids through bordered pits. The ‘“Schlafende Augen,’ or 
parenchyma strands, in the cortex and along the line of medullary 
rays in the wood as well as the patches of abnormal or partially 
developed tracheid tissue are the result of the stimuli proceeding 
from hyphae that were nearby at the time this tissue was being de- 
veloped. It is difficult to understand how a cambium cell harboring 
a hypha could divide at all, or how a tracheid could change its form 
once it has become lignified. 
The cambium reacts in such a way as to cut off by the excessive 
development of tracheids certain fascicles of hyphae and thus 
check the radial and longitudinal advances of the fungus. The 
apparently isolated patches of mycelium found in the heart wood are 
nevertheless quite generally connected above or below with some 
radially placed strand that ultimately reaches the cortex. This may 
be the main reason why one finds living hyphae deeply imbedded 
beneath several rings of wood. 
Haustoria may occasionally be found in cells of the cortex medullary 
rays, but they are not abundant. Some of these haustoria are bi- 
nucleated. 
There seems to be no question that Wo6rnle was right in stating 
that the hyphae of G. Ellisii are intercellular. 
GYMNOSPORANGIUM BISEPTATUM 
Harshberger and Wornle disagree on a second important point in 
their studies of G. biseptatum. This relates to the presence or absence 
of mycelium in the wood cylinder of the cedar. 
I have as yet been unable to infect the cedar with this species. 
I have studied specimens naturally infected and especially one from a 
