PESTS OF .THE VINERY AND STOVE. 



323 



Discoloured Vine Leaves. 



Discoloured Vine leaves are continually turning up without furnishing 

 any clue to the cause. These are mostly discoloured in large bright 

 blotches, which are sometimes yellow, as in some forms of the " Californian 

 Vine disease ; " or dark red, as in the " Sicilian Folletage ; " or red, brown, 

 and yellow, as in the Italian " Mai Nero." They appear to give evidence 

 of some form of organic disease, and yet to evade all microscopical 

 scrutiny, and after many years to remain as great a mystery as ever, and 

 consequently without the suggestion of a remedy. 



U.S.A. Beport Dep. Agri. 1892. 



CONSERVATOBY PARASITES. 



Separate from the fungi which affect garden plants there are a few 

 that are troublesome in the stove and conservatory, and these could not 

 be excluded from the present enumeration. In this connection the list 

 might have been much extended, but the persons interested would be 

 necessarily limited, as compared with those who confine themselves to out- 

 door culture. 



Sooty Mould of Orange. 

 Fumago\vagans (Pers.), PI. XIV. fig. 21. 



This black mould is familiar enough, as it occurs on the foliage of 

 numerous trees in this country, and especially such as are subject to 

 honeydew. It forms black patches on the leaves, to such an extent as to 

 form a crust, but in this condition it is simply an imperfect fungus, and 

 may develop into a species of Capnodium or Meliola, as the case may be. 



The creeping mycelium is branching, and closely adnate to the 

 matrix, sometimes confluent and forming cellular ganglia, or torulose, like 

 a string of beads, constituting an effused thinly membranaceous stratum, 

 which is apt to flake off when dry, and resembling a coating of soot. 

 Short fertile branches arise from this mycelium, which are more or less 

 branched ; conidia at the tips of the branches, often forming short chains, 

 sometimes one-celled, usually two-celled, and sometimes three-celled 

 (5-15 ^ long), dark brown. 



It is found throughout Europe and North America, and in parts of 

 Asia, but it is scarcely probable that we shall be troubled with the 

 advanced stages in this country, whether Capnodium, Meliola, or any of 

 their kindred. 



Sacc. Syll. iv. 2618 ; Journ, B.H.S. iv. 251 ; U.S.A. Dep. Agri. 

 Bull. 8, pi. vii. ; Mass. PI. Dis. p. 101, f. 17. 



Specking of Citrus fruits, in Australia, has been attributed to a mould 

 fungus Penicillium digitatum, causing a loss of from 2 to 50 per cent, on 

 fruit shipped during the season. 



Journ. B,H.S. xxviii. p. 243. 



