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[Vol. 11 
color. These masses of spores, being in a sticky mass, at first might 
readily be carried by mammals, birds, or insects, and later when they 
have dried, are disseminated by the wind. After June the course 
of the disease is arrested until the following spring, wherein it is unlike 
the chestnut blight ( Endothia parasitica) , although in April or May 
these diseases have such points of similarity as the yellow exuding 
mass of spores, the erumpent pycnidia, and the sunken areas of dis¬ 
eased bark. 
Affected trees at once attempt to repair the wound and by July and 
August may have progressed so far as to entirely cover the open wound 
with a growth of cambium, which in such cases forms a knot of varying 
size. In every case where this is cut into, the dead area caused by the 
canker is easily exposed. The disease continues to progress the 
following year, although apparently healed over after the first attack. 
Where trees have been weakened year after year by attacks of the 
canker, they become unable to counteract the disease by a fresh 
growth of cambium. Large unhealed cracks and fissures remain in the 
bark and the tree soon dies. 
Dothichiza populea was first described and named in 1884 by Saccardo 
and Briard. In 1903 Delacroix ascertained that the fungus was 
parasitic in nature and was the cause of a serious disease attacking 
Populus nigra, P. deltoides and P. bolleana. Hedgcock and Hunt of 
the Bureau of Plant Industry have made the most extensive studies 
of this and other poplar diseases in tlje United States and have con¬ 
tributed the only literature on the subject in this country, consisting 
of a short paper in vol. VIII of Mycologia for November, 1916. These 
writers conclude that the disease was probably imported on nursery 
stock previous to the enforcement of the present inspection laws 
and that it is a somewhat recent disease in the United States. 
The disease was by no means confined to nurseries. The trees in 
private estates in many cases were seriously attacked, and very few 
of the trees along roadsides or the railroad right of way had escaped it. 
A systematic course has been pursued with reference to the disease 
in nurseries of this state. All blocks of poplar have been carefully 
examined and diseased trees have been marked for removal. The 
various nurseries have cooperated cheerfully in this destruction of 
cankered trees. This treatment has been severe, but no other means 
of control could be more efficient. In the only nursery of the eastern 
section of the state which had poplars entirely free from the canker, 
the trees were regularly sprayed every winter with lime sulphur. 
In no other nursery had the poplar trees been sprayed. This would 
indicate lime sulphur as a helpful fungicide. Landscape architects 
now specify that Lombardy poplar trees must be branched from the 
