24 



our wild Roses, and may frequently be found on shoots 

 growing from stocks of standard Roses in neglected 

 gardens. 



Three different kinds of fruit are produced, two 

 kinds of summer spores, aecidiospores and uredospores 

 respectively; these follow each other in the order named, 

 and appear under the form of deep orange, powdery 

 patches on the leaves and wood. The patches on the 

 leaves are usually small, but when several are present 

 they frequently grow into each other, and then frequently 

 cover the greater portion of the surface of the leaf (see 

 Plate II., Fig 2). 



On the wood the patches of rust are often large, 

 extending to one inch in length, and often cause 

 distortion or curving of the part affected. When the 

 rust disappears gaping wounds or canker spots remain, 

 which favour the growth of other kinds of fungi. 



During the autumn the winter form of fruit appears 

 on the under surface of the fading leaves, under the 

 form of minute black, projecting points, which are 

 usually uniformly scattered over the entire surface of the 

 leaf. These black points consist of clusters of winter 

 spores, which remain on the dead, fallen leaves in a 

 resting condition until the following spring, when they 

 commence growth afresh and produce exceedingly minute 

 spores, technically known as secondary spores. These 

 secondary spores infect the young leaves and wood, and 

 give origin to the orange summer form of the fungus 

 (see Plate II., Fig. i). 



PREVENTIVE MEASURES. 



To prevent a recurrence of this disease it is 

 imperative that all leaves bearing winter spores should 

 be collected and burned. This applies equally to fallen, 



