PESTS OF THE VINERY AND STOVE. 



319 



Tucker i, and probably was so accepted before the discovery of the perfect 

 fruit. 



The first stage is the creeping mycelium and white mould, which 

 covers the leaves, wholly or in patches, and this is followed by the 

 presence, amongst the mycelium, of the little globose conceptacles, attached 

 at the base, and furnished with a circle of appendages or flexuous 

 threads, as in other species of Erysiphc, such as the one upon the Garden 

 Pea, but less distinct and more interwoven with the mycelium. The re- 

 ceptacles contain four pear-shaped sacs or asci, each of which contains 

 two sporidia (18 x 9 /i), which are elliptical and colourless. 



It was first made known and described in 1887. 



The same remedies are recommended as have been applied in the case 

 of the English Vine mildew, and doubtless the persistent application of 

 sulphur will bring its reward. 



Grevillca, xv. 98; Sacc. Syll. x. 1571. 



Black Rot of Grapes. 

 Guignardia Bidiucllii (Viala), PI. XIII. fig. 9. 



Doubtless one of the most destructive of our American Vine pests, 

 which manifests itself in variable forms, found its way into Europe in 

 1885 with imported vines. 



Young shoots and leaves are first attacked, under the form of small 

 brownish blotches. A fortnight later the fruit shows symptoms of 

 disease by the appearance of small blackish spots ; afterwards the fruit 

 turns black, shrivels, and becomes hard. At this stage the surface of the 

 patches is seen to be studded with little black points, indicating what are 

 termed the pycnidia form of the disease, or the summer fruits. These 

 receptacles contain innumerable minute bodies, or stylospores, which are 

 produced in the interior, and when mature ooze out through a pore at the 

 apex (7-8 fx long). This is the condition which was first known, and was 

 then called Phoma uvicola. The stylospores, after their escape, are 

 carried about by moisture over the surface of healthy grapes, where they 

 germinate at once, enter the tissues, form a diseased spot, and thus dis- 

 tribute the disease. 



Later on other forms of summer fruit supervene, until the final or 

 highest form of fruit appears on the diseased grapes lying on the ground 

 during the winter. In this stage the sporidia are produced in cylindrical 

 cells, or asci, and come to maturity in the spring. They are almost 

 elliptical, without division, and colourless (12-17 x 4^-5 //). 



In the United States spraying with Bordeaux mixture is much relied 

 upon. 



Gard. Chron. January 26, 1895, p. 101, fig. 18 ; Mass. PL Dis. p. 105 ; 

 Thiim. Pilz. Wein. p. 15C, f. 11 ; Tubeuf, Dis. p. 216. 



Vine Sclekotinia. 

 Sclerotinia Fuckcliana (De Bary), PI. XIV. fig. 11. 



This Vine pest appears also under two or three forms, the earliest 

 being that of a mould, representing the conidia, and not uncommon on 



