26 Letters on the Diseases of Flants. 



Fig. 28.— Tlie disease Melauose (P), as it appears on the fruit and leaves of orange-trees at Pennant 

 Hills, about 10 miles from Sydney, N.S.W. The two left-hand oranges show the disease without 

 any complications, the upper one more especially showing the arrangement of the small diseased 

 spots in archipelago-like groups, while the lower shows a more advanced stage of the disease in 

 which the spots have run together (lower left-hand part), or have developed a distinct mycelium at 

 the edges (upper right-hand part). The right-hand orange shows the disease Maori as well as 

 Melanose, this latter disease appearing somewhat in the shadow of the leaves, while the Maori is 

 most conspicuous on the extreme right. All the leaves show Melanose (?), but it is most marked on 

 the lowest leaf. The bark of the young twigs is also slightly attacked. As this photograph was 

 taken in the orchard from perfectly fresh material the effect is very faithful and lifelike. 



