389 | H. 8. Fawcett 191 
An interesting example of an old, well-known disease with 
a rather limited distribution is melanose, which is due to 
Phomopsis citri. The fungus produces small, brown pus- 
tules on the surface of rapidly growing leaves, twigs and 
fruit. It was discovered in 1892 and was first definitely 
described, by Webber, in 1897. At that time melanose was 
already a rather serious disease in the middle portion of the 
peninsula of Florida. During the past 20 years, citrus 
nursery stock has been freely interchanged between different 
parts of Florida, and thousands of acres in Cuba have been 
brought into citrus culture for the first time, the stock for 
planting being derived from Florida, and yet the area over 
which the disease is now of serious commercial importance 
is confined roughly between the parallels of 2714° and 
291° N. latitude in Florida. 
Southward from this area melanose gradually becomes 
less and less severe and it finally disappears entirely, so that 
the southernmost citrus districts of the state are free from 
it. In Cuba, if the disease occurs at all, it is of uo commer- 
cial importance; I was unable to find any evidence of it in 
the island in January, 1914. North of the Florida area of 
most serious injury, melanose occurs in a less severe form, 
and a mild form of the same disease has been reported for 
southern Alabama and Louisiana, but it is apparently not 
serious in these regions. No trace of this disease has ever 
been found in California. 
The same Phomopsis that produces melanose also plays a 
part in the so-called stem-end rot of mature or nearly mature 
citrus fruits, and it is an interesting fact that this fruit rot 
has never been known to be serious outside of the areas 
where melanose is also of commercial importance. Like 
melanose, stem-end rot has not been reported as occurring 
either in Cuba or in California. 
The reasons for the peculiar distribution of Phomopsis 
citri, as above described, are not at all understood, and we 
cannot regard our knowledge of melanose and stem-end rot 
as at all nearly complete until a properly substantiated ex- 
