a parasitic Fungus on Sugar-Cane and Cacao . 687 
of ripe sugar-cane in distilled water for half an hour, boiling, 
and then filtering. It was found that the addition of the 
small quantity of tartaric acid was sufficient to check the 
development of Bacteria in the hanging-drops, and to permit 
of the mycelium developing in such a way as to obtain pure 
cultures from the drops. 
The ripe spores germinate in from three to six hours after 
sowing by sending out a colourless hypha from one of the 
compartments of the spore, which contains finely granular 
protoplasm (Fig. 4). The hypha grows in length, slowly at 
first, afterwards much more rapidly, and then branches : about 
twenty-four hours after sowing septa begin to appear. 
In cases where spores are sown which are still colourless 
and have not yet developed the transverse wall, germination 
is more rapid than in the case of ripe spores, and takes place 
in less than two hours after sowing. The earlier stages in the 
germination of such a spore are shown in Fig. 5. 
Two days after sowing, fusion of hyphae was common in 
the drops. A young hypha approaches very close to one 
somewhat older, and the advancing tip of the young hypha 
curves round to meet a short branch pushed out by the older 
filament, and fusion rapidly takes place (Fig. 6). Where, 
hyphae have crossed in the older regions of the colony a short 
process is sent out near the crossing from each of the hyphae, 
and these fuse. 
About this time the hyphae commence to grow down into 
the moist air below the drop, and their development goes on 
until the mycelium reaches the water on the floor of the 
culture-chamber, where considerable subsequent growth takes 
place. The appearance of these positively hydrotropic columns 
of mycelium reminds one somewhat of the hanging roots of 
the banyan : the appearance is shown in Fig. 7. From the 
point of view of pure cultures this aerial development is an 
obvious advantage, since further cultures which proved to be 
free from Bacteria were obtained by infecting flasks of sterile 
food-material, and tubes containing sterile wood, with portions 
of this mycelium developed from a single spore. 
