DISEASES OF THE QUINCE. 93 



6. LEAF BLIGHT. This is very unlike the leaf blight 

 of the apple and pear. The specimens examined have 

 not yet revealed to us the cause. It first appears on the 

 edges of the leaves ; sometimes on one side only, but more 

 generally reaching nearly all the way around the leaf. At 

 first it is of a reddish brown ; but as it extends inward 

 toward the mid vein, it gradually assumes a deeper hue, 

 till at last it is almost jet black, and covers very nearly 

 all the blade of the leaf. As the disease progresses the 



Fig. 66. LEAF BLIGHT. 



edges of the tenderer leaves curl upward, and eventually 

 the whole dies and falls. 



7. QUINCE ROT (Sphceropsis Cydonice, C. and E.). 

 This disease usually begins at a few points on the surface 

 of the fruit, and spreads regularly in enlarging circles 

 until the whole fruit is decayed. As these spots enlarge, 

 the centers grow dark, and soon may be seen as a mass of 

 black points, which contain a multitude of brown spores, 

 each capable of spreading the disease. A sound quince 



