86 



JOURNAL AND PROCEEDINGS. 



and Mikado, seem very subject to it, while Perfection, Paragon and 

 Trophy are less so. The appearance of the affected fruit is shown 

 in fig. lo. 



By scientists it is called Macrosporium Salani. The fungus con- 

 sists of a dark colored mycelium or vegetable system, the growing 

 tubes of which can -be readily traced to the cells of the sound tissue 

 of the tomato, (see fig. ii«), and of spores, which are borne on 

 the end of branches, called hyphse, represented in fig. w^ b and 

 c. These are at first dark brown, but at length turn olive-black. 

 When these spores come in contact with green or ripe fruit, they 

 germinate rapidly under favorable circumstances, such as heat and 

 moisture, and send out slender tubes, shown at fig.' d. These spores 

 survive the winter in the shriveled fruit, and in old leaves and stems. 

 The remedy proposed by the United States Department of Agricul- 

 ture is : One-half ounce sulphuret of potassium, dissolved in a gallon 

 of water, and sprayed upon the vines, so as to thoroughly wet all 

 the fruit. 



'W^ 



Fig. 11. 

 The Powdery Mildew of the Grape {Uncimda spiralis) is 

 quite common in the Niagara district, and in some varieties very 

 injurious. It appears first early in June, in the form of dull greyish 

 white patches on the leaves and fruit. Under the microscope these 

 patches are seen to be the mycehal growth of the mildew which 

 spreads over the surface of the host plant, and does not penetrate its 



