15 
FALSE MELANOSE. 
( Gladosporimn brunnco-atrum n. sp.) 
This disease is unknown in Victoria, but it occurs in the orange 
groves of New South Wales to an alarming extent. It was con¬ 
sidered by Dr. Cobb to closely resemble a disease in Florida, 
known as “Melanose,” and bo named it accordingly, the term 
being derived from two Greek words meaning “ Black Disease.” 
In Florida, where investigations into I lie principal diseases of 
citrus fruits were carried out during three years by Messrs. 
Swingle and Webber, there was a disease, first noticed in 1892, to 
which they gave the above name, although the cause of it has not 
yet been discovered. It was suspected to be due to some vege¬ 
table parasite, but the microscope failed to reveal it. It seemed 
to be contagious, infection only taking place when the tissues 
were quite young, and the entirely local nature of the disease 
appeared to point to a parasitic origin. “ The strict localization 
of the disease, so similar to what occurs in scab, again strongly 
suggests that the disease is caused by some vegetable parasite.” 
No definite organism, however, was found associated with the 
disease. 
Then, in 1897, Dr. Cobb published in the April part of the Agri¬ 
cultural Gazette of New South Wales, an account of a prevalent 
disease on citrus fruits in that colony, which he had little doubt, 
was identical with the Florida disease, so he named it “ Melanose,” 
but with a mark of interrogation. He found, however, a fungus 
associated with this disease, consisting of mycelium and conidia, 
of which lie givos a drawing, but made no attempt to determine 
its nature. Next, in 1898, Trabut* determined the “Melanose,” of 
mandarins to be caused by a Septoria , which he named Septoria 
glaucescens . The interest of this discovery lies in the fact that there 
is a disease of vines also called “ Melanose,” and produced by a 
fungus belonging to the same genus, viz., Septoria ainpelina, Berk 
and Curt. The leaves are studded with numerous, small, reddish- 
brown, or black dry spots, hence the common name. According 
to a recognized law of naming, this will be the true “ Melanose,” 
since it is caused by a similar fungus to that on the vine, and the 
so-called “Melanose” of citrus fruits being produced by an entirely 
different fungus will require to be re-named. 
I have determined the fungus causing this disease in Australia, 
which belongs to the scab-producing sort, and it need hardly be 
pointed out, that the more accurate the determination of the 
cause, the more likely is a rational method of treatment to be 
adopted. 
* Comptes Rend. d. stances de l’Acad. d. sc. t. CXXVI. n. 7 (1898). 
