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This is also frequently the case with a single branch. In such cases 
the trees usually die outright in a few weeks and never put out any 
new growth from the trunks. Again, a single branch may wither as 
suddenly. In the great majority of cases, however, a vigorous new 
growth pushes out from the trunk at the beginning of the rainy season 
and at first it would seem as though the tree would recover. Some- 
times such sprouts continue growing vigorously two years or more, 
but sooner or later they show smali and usually yellowish leaves and 
begin to decline. Often, too, such shoots wilt and show all the symp- 
toms of a fresh case of blight. Ordinarily the tree continues to decline 
gradually, and is finally removed before it dies, to make place for a new 
tree. Again, cases may linger ten years or more, making a Slow, sickly 
growth, and even bearing a little fruit. Cases of real recovery from 
genuine blight are, however, almost entirely unknown, although hun- 
dreds of growers have been deceived by the vigorous growth of water 
sprouts sent out by blighted trees after the first wilting. | 
A most remarkable fact is that the roots of blighted trees invariably 
seem to be entirely healthy. The vigorous growth of water sprouts 
they support shows that they are capable of considerable functional 
activity. . | 
No anatomical features which are characteristic of blight have yet 
been found. Under the highest powers of the microscope the tissue of 
every organ of blighted trees appears to be normal, which is in striking 
contrast to foot rot and die-back. The physiological activity of the 
leaves and branches, however, is very much deranged, as has been 
proved by experiments on the loss of water from blighted twigs. 
Varieties of trees attacked.—Almost all citrous fruits are attacked by 
blight, although some sorts are nearly exempt. Common oranges (Citrus 
aurantium), tangerines and mandarins (Citrus nobilis), and grape fruit 
(Citrus decumana), in about the order named, are the most susceptible. 
Lemons blight less than any of the fruits mentioned, while limes and 
sour oranges, especially the latter, are almost exempt from this disease. 
Certainly not more than one sour orange tree in a thousand is blighted 
even in regions most liable to the malady. Curiously enough, the sort 
of stock used appears to have no influence in increasing or diminishing 
the susceptibility of trees to the disease. Common oranges budded 
on sour orange roots are apparently as liable to blight as are sweet 
seedling trees. 
Situations most liable to the disease.—Although blight attacks citrous 
fruits growing on all kinds of soil, it is most common on trees growing 
on very light, sandy hammock! (Pl. II). Such soils are usually com- 
posed almost wholly of sand, with an admixture of decaying vegetable 
matter; sometimes, however, they are underlaid at a depth of from 4 to 
12 feet with clay or hardpan (sandstone). Trees growing on clayey 
1 Hammock land is that which was originally covered with hard woods, especially 
live oak, magnolia, hickory, etc. 
