28 MASSACHUSETTS HORTICULTURAL SOCIETY. 



preserve their health. The fungus Pliyllosticta macuUcola Hals., 

 is recognized by producing small brown angular spots in the 

 leaves, which finally show spore-bearing pimples. 



There is a tip blight of Dracecna fragrans that often greatly 

 disfigures the otherwise highly prized plants. "It is often the 

 tips of leaves that are most subject to the bad effects of the 

 blight, and this is true of many other than the Dracaena plants. 

 This may be due to the fact that the water holds to the pendent 

 tips longer than to any other portions. When the plants are 

 sprinkled the upper portions of the foliage retaining only a film of 

 the liquid quickly dry off, while the water descending to the tips 

 remains there for a long time. The presence of this moisture 

 upon the surface of the leaf-tips furnishes the proper conditions 

 for the germination of spores that may have been brought there 

 by the descending water as it flowed along, gathering to itself the 

 spores previously deposited upon the surface of the leaf. It is 

 thus seen that there are* at least two good reasons why the tips of 

 drooping leaves may, be infested with fungi while the upright parts 

 escape. As a matter of fact, however, such portions do not 

 wholly escape. Not infrequently in the case in hand, the 

 Dracaena leaves may be blighted midway of tips and base. In 

 such instances it is possible that at some time there has been some 

 injury b}' means of which the spores found an easy place to 

 germinate, and their germ tubes to penetrate the leaf. 



There is a third reason why the tips are more susceptible, 

 namely, the greater surface exposed in proportion to the amount of 

 tissues, than in the other parts of the leaf. The entrance of disease 

 germs is largely a surface action, and therefore the chances are 

 greater as the tip of the leaf is approached. The tips being 

 thinner and farther from the base of interior water-supplies, often 

 suffer from wilting, and become dried naturally. Anything of 

 this nature assists the parasites to get a foothold. The wonder is 

 that more tips are not attacked. When once a fungus ha& 

 established itself, it will begin to work its way in the leaf toward 

 its base. This advance may be quite uniform and rapid, so much 

 80 that there is a distinct line between the living and the destroyed 

 tissue."* 



Fungous Diseases oj Palms. The growers of palms are far 

 from exempt from troubles of a fungous nature. It is difficult to 



*From the writer's Report from the New Jersey Experiment Station for 1893 . 



