378 Howard . — On some Diseases of the 
selected. Six were used as controls and twelve were in- 
oculated at wounds, six with Melanconium spores from a pure 
culture and six with similar spores and food-material. The 
places where the wounds were made were cleaned with alcohol, 
and flamed with a spirit-lamp. The holes were cut with 
a sterile knife, and after inoculation were bound up with 
sterilized tape which had been soaked in paraffin wax. The 
control canes were treated in a similar manner, but in this case 
no spores were introduced. On December 28 these canes were 
examined. In no instance had the mycelium spread to any 
extent, except immediately above and below the wound where 
it reached the nearest nodes. The affected tissues were bright 
red as before, and the canes exhibited no trace of the ‘ rind ’ 
disease. The controls showed no infection, although the 
cells round the wound were bright red and the bundles cut 
through showed gumming in the large vessels. Possibly this 
formation of gum is an adaptation on the part of the cane 
to prevent Bacteria and Fungi passing into the vessels where 
it is wounded. 
2. On December 10, four healthy White Transparent canes 
were inoculated with Melanconium spores from a pure culture 
at wounds made with a sterile knife as above. Four other 
canes from the same stool were used as controls. Thirty 
days afterwards the canes were examined. In all cases the 
tissues were brownish-red above and below the wounds, but 
no difference was evident between the inoculated canes and 
the controls in this respect. On examining the inoculated 
canes it was found that the mycelium of the fungus had in all 
cases spread in the tissues immediately above and below the 
wounds as far as the nearest nodes, but it could not be traced 
beyond the vertical column of tissue containing the wound 
and bounded by the nodes above and below this aperture. 
The characters of the invading mycelium were identical 
with those of the hyphae developed in artificial cultures of 
Melanco 7 iium spores. In no case was any mycelium noted 
in the control canes. 
3. On December 19, four healthy White Transparent canes 
