10 
BULLETIN 5 9, HAWAII EXPERIMENT STATION 
knife. Each graft was made with thoroughly cleansed knife and 
hands to prevent infection by bacteria, dirt, and the like. Even the 
oil remaining on the blade after whetting was removed with alcohol, 
Figure 5. — Seedling Macadamia trees which have been caused to root by the air- 
layering method of rooting plants 
and the knife was dried with a clean piece of cheesecloth. From 
the beginning of the cut to the completion of the union the work was 
done without delay. The cut surface was made about 2% inches 
long, it was smoothed off, and the edges were not bruised. A tongue 
