328 BOTANICAL GAZETTE [ NOVEMBER 
other plant products, occurring at different seasons of the year. 
Thus Busse” found that the maximum amount of starch in the 
growing point of A. pectinata occurs in May, and that from this 
month on there is a decrease until in the fall and winter, when 
the minimum is reached. He found also three different tannins 
in the growing point, varying in amount at different seasons of 
the year. 
It often happens that buds are found which have been killed 
by the mycelial infection of the growing point. That this 
infection has taken place from the inner scales there can be no 
doubt, since the mycelium hibernates here, and infects the 
rudimentary leaves and young shoots as soon as they begin to 
develop in the spring. The mycelium is thus evenly distributed | 
in the bark of all diseased shoots above the tumor of the 
affected branch. If it were not for this mycelial infection of 
the young shoots and rudimentary leaves by the bud scales 
and parenchymatic tissue of the primary cortex, healthy leaves 
would be found on affected branches. This never occurs. It 
often happens, however, especially on the witch broom of A. 
pectinata and A. firma, that the leaves and young shoots are not 
infected. They then develop like the normal. This shows that 
the mycelium does not spread to any great extent in the bark 
after the tissue differentiation has taken place. The my celium 
never spreads more than 2 to 3™ each year in the healthy bark 
below the swelling or tumor. 
V. ANATOMY OF THE NORMAL AND DISEASED SHOOTS AND BRANCHES: 
1. Normal shoots and branches.—The leader or terminal shoots 
depart in their general characters from the lateral, not only 
the morphology and anatomy of their leaves, but also in the 
anatomy and morphology of their axes. The leader shoots are 
longer and have a greater diameter than the lateral. * = 
greater diameter is due mainly to the greater developmen® 
the pith and primary cortex, the most important conducting 
tissues of the first year’s internode. The vascular bundles of - 
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