148 
of growing mycelium into living trees in the propagating houses 
caused the death of infected branches and produced abundant 
fruit in from four to six weeks. One or two of these young trees 
appeared to be able to resist infection altogether, and a few of the 
older trees in the Garden are apparently immune, at least when 
in vigorous health. 
In its effect on the host, this fungus may be classed with the 
most destructive parasites ; the parts attacked being so vital and 
Fic. 16. Fruiting pustules and spore masses from chestnut cultures, “16. 4. Stages 
fn : TF f .16. 4. Stag 
in the development of the pustules. 8, C, D. Various forms of spore discharge in a moist 
atmosphere. ‘ Bias 
