PESTS OF THE VINERY AND STOVE. 



315 



preserving constantly a definite outline. This spot separates readily from 

 the subjacent pulp, in consequence of a copious crop of mycelium, the 

 threads of which form the radii of a circle. The surface is rough with 

 little raised orbicular reddish perithecia, or conceptacles, for there are 

 no true perithecia, which are arranged in circles. The conidia are pro- 

 duced within the conceptacles or cells, and are oblong, withe ut any 

 division as yet observed, but constricted in the middle, and colourless 

 (15-20 /u long). In age the false perithecia fall away, leaving a little 

 aperture, the border of which is often stained black. 



We have assumed this to be a Glceosporium, most certainly not 

 Ascochyta, as first described, but we have not been fortunate enough to 

 meet with it. It seems to be distinct from Glceosporium uvicola on 

 grapes, but may be a form of Glceosporium fructigentm, which is said to 

 occur on grapes as well as on apples. 



Gard. Chron. 1854, p. 676; Cooke, Hdbk. No. 1358. 



Australian anthracnose, Glceosporium bicolor (McAlp.), is the Apple- 

 rot of Australia. 



Grape Rot. 

 Glceosporium uvicola (Berk.), PI. XIII. fig. 4. 



There is some confusion in the records of this species, which has also 

 been called Glceosporium Iceticolor, but the proper host of that species is 

 the Peach and Nectarine. 



The spots are always of a pale orange, with an almost white spot in 

 the middle. The tendrils of spores, or conidia, are similar in colour, and 

 the conidia are larger than in the species upon Peaches (25 n long). 

 Fortunately [it is a very rare species, and is not likely to cause much 

 annoyance. 



Berk., Gard. Chron. 1854, p. 676 ; Sept. 9, 1871, p. 1162. 



Grape Anthracnose. 

 Glceosporium ampelophagum (Pass.), PI. XIII. fig. 5. 



This attacks Grape Vines in Italy and the United States, but until 

 recently there has been no record of it in Britain. It attacks all the 

 green parts, and internally exhibits very little mycelium ; the pustules are 

 without definite receptacles, and the conidia are produced on short stalks 

 within definite cells ; when mature they escape by rupture of the cuticle, 

 and lie like a crust on the surface until dissolved by moisture (5-6 x 2^ f.i), 

 when they float away to infect other parts. (Fig. 76.) 



Gard. Chron. July 8, 1893, fig. 10 ; Mass. PI. Dis. p. 279 ; Sacc. Syll. 

 iii. 3755 ; Thiim. Pilz. Weill, p. 9 t. 3, f. 24 ; Thiim. Pock. d. Wein. 

 (1880) ; Sacc. Syll. iii. 3755 ; Tubeuf, Dis. p. 484. 



White rot of Grapes, Coniothyrium diplodiella (Speg.), occurs on the 

 fruit, leaves, and rarely on twigs. It is uncertain whether it is truly a 

 parasite. The coloured sporules are 7-11 x 5^. This pest has recently 



B 2 



