FUNGOID PESTS OF CULTIVATED PLANTS. 131 



a short beak, or ostiolum, which pierces the surface. Within the receptacle 

 cylindrical cells, or asci, are produced, each of which contains eight 

 elliptical sporidia, which are colourless and divided by a central septum 

 into two cells (18 x 5-6 p), each cell enclosing two guttules, and terminated 

 by a curved hair-like appendage, which soon falls away. (Fig. 17.) 



Known in Germany, Switzerland, and Italy ^ 



All the dead hanging leaves should be collected and burnt. Frank 

 says that in one district in Prussia this method was carried out for two 

 seasons, after which the Cherry crop, which had been ruined, was 

 restored. 



Sacc. Syll iii. 2637, i. 2214 ; Mass. PL Dis. p. iii. fig. 19 ; Journ. 

 B.H.S. xxv. 1901, p. 313, fig. 162, xxvii. p. 1140 ; Tubeuf, Dis. 222. 



SHOT-HOLE FUNGUS. 



Several species of leaf-spot have been recorded in Australia, and else- 

 where, attacking leaves of Plum and Cherry, forming round spots, the 

 dead tissue of which soon falls out and leaves a round hole in the leaf. 



American shot-hole fungus (Septoria cerasina) occurs on Plum and 

 Cherry leaves, and has strongly curved conidia (50-75 p long). 



Another shot-hole fungus (Cylindrosporium Padi) having curved 

 filiform conidia (48-62 X 2 //) occurs also in the United States. 



An Australian shot-hole fungus (Phyllosticta prunicola) affects the 

 leaves of Apple, Plum, and Cherry in similar manner in Italy, and extends 

 to Australia (5x3 /i). 



The genuine Australian shot-hole (Phyllosticta circumscissa), as it 

 claims to be, attacks Cherry and Peach leaves (8x2 /*). 



Besides which a white mould (Ovularia circumscissa) is credited with 

 forming similar shot-holes in Cherry leaves in Russia (15-18 x 6-7^). 



And a black mould performs the same office (Cercospora circumscissa) 

 upon Plum leaves in the south of Europe, in the United States, and in 

 Australia (50 x 3^-4 /*, 3-4 septate). 



Still another shot-hole fungus, and one of the most common in 

 Australia, is a black mould (Clasterosporium carpophilum) on Peach, 

 Almond, Cherry, and Apricot (54 x 14 /z, 4-5 septate).- -This is known also 

 in Italy, Switzerland, Austria, and Portugal. 



Strange that none of these should yet have paid a visit to Britain. 



Me Alpine Fung. Dis. p. 33. 



A shot-hole fungus has been found lately, ^several times affecting 

 Peach leaves in this country, but not having seen it ourselves we are 

 unable to determine the precise species of fungus implicated. 



A correspondent (Gard. Chron. Oct. 14, 1905, p. 282) states that he 

 has used Campbell's Sulphur Vaporiser with good effect, 1 but was not 

 successful by spraying with Bordeaux mixture. 



AMEEICAN BLACK KNOT. 



Plowrightia morbosa (Sacc.). 



Although this is an American disease, unknown in Europe, it is the 

 worst enemy of the Plum and Cherry in the United States. It forms 

 black rough excrescences on the branches, often several inches in length. 



K 2 



