112 
Spread. 
By virtue of the superficial strands the fungus possesses an excel- 
. lent means of propagation. A careful search has failed to demonstrate 
the presence of any spore-bearing organs, nor were these developed 
when the mycelium was placed in a moist chamber and kept for 
several weeks. It may, therefore, be concluded tl^at the primary 
means of propagation is by the 'Vegetative strands and that this is 
accompanied by a suppression or partial suppression of the spore- 
bearing organs. 
It has been possible to trace the mode in which infection occurs 
in the field. Here and there infected leaves have been blown by wind 
and lodged against a branch. The mycelium on the leaf accumulates 
a dense growth by which the leaf is made to adhere closely to lhe 
branch. From this point strands arise and traverse the branch in all 
directions. Infection was also seen to pass from a branch on an in- 
fected tree to a healthy tree through the leaves of adjacent branches 
being in contact with each other. Again, in the case of two camphor 
plants, the strands were seen to pass from fallen leaves on the ground 
up the branches and to reach the younger twigs. 
The mycelium of the fungus is very sensitive to moisture and to 
contact. The former is illustrated by the dense growth which is ac- 
cumulated when the mycelium is placed in a moist chamber and when 
the mycelium reaches the more shaded and damper portions of a 
branch. The latter is shown by the rapid growth of the mycelium 
where two leaves or twigs come into contact with each other or where 
an infected leaf lodges against a branch. 
Distribution. 
Judging by analogy with other “thread-blights” one may well 
expect that this fungus comes in from the jungle; and the close 
proximity of the plants hitherto attacked to the jungle is in favour of 
this conclusion. In neither case, however, was it possible to make an 
examination of the jungle adjacent to the infected area. 
The fungus on Hevea and the one on camphor were, as far as can 
be ascertained by an examination of sterile mycelium, identical with 
each other. A fungus which is similar in all respects to the one on 
Hevea has also been found on Guava ( Psidium Guyava). From what 
is known of fungi of this nature it is improbable that in the jungle it 
should confine itself to even a few different plants. 
Other Thread-Blights 
Several fungi of a similar nature have been described from differ- 
ent parts of the world.- The best known of these is, perhaps, the 
