82 JOURNAL AND PROCEEDINGS. 



affected with the bhght. Besides this, he found that the blight 

 could not be communicated to healthy trees by the juices of the 

 disease, after the germs were removed from them by filtration, 



The same organism causes the twig blight of the crab apple, 

 the quince and even, to some extent, ordinary cultivated varieties 

 of the apple. 



Prof Burrill told me, at the time of the visit referred to, that 

 the bacterium of the pear blight ordinarily comes through the young 

 and succulent wood of the trees and also through the stomata of the 

 leaves and blossoms in the early part of the growing season. This 

 explains why pear trees, which are stimulated to make a very rapid 

 and succulent growth, are more subject to the blight. The little 

 bacterium, according to Mr. Burrill, has a sort of corrosive nature 

 which enables it to pass through the cellular tissue from cell to cell, 

 thus working along through the wood, carrying destruction in its 

 course. 



Still the pear blight is only a half solved problem. It yet re- 

 mains to be shown how we may prevent its ravages and how to save 

 the trees that are already affected. Spraying with the Bordeaux 

 mixture early in summer, has been recommended by the U. S. 

 Department of Agriculture as being of great value in preventing 

 leaf blight. 



One of the greatest plagues of the fruit grower is the Apple 

 Scab. This has been known to botanists on the continent of 

 Europe for some fifty years, but, since the year 1869, its habits have 

 been more carefully observed by mycologists, who have named it 

 Fusicladium dendriticum. We gave some space to its description in 

 The Canadian Horticulturist, volume X, page 103, and since that 

 time have endeavored to keep apple growers posted concerning the 

 progress of the evil and the success of the various remedies proposed 

 for its destruction. At that time it had reached Australia ; now we 

 have reports of its presence even in New Zealand. 



An important step in advance was made when it was shown that 

 the fungus causing the leaf blight of apple, which resulted in its 

 early dropping from the tree, was identical with that known as the 

 scab on the fruit itself 



On the leaves, the scab appears first as small olive-green spots, 

 of a definite and rounded outline (fig. 6). These increase in size, 

 and assume a velvety appearance, with a less regular border ; some- 



