190 "Spotting" of Apples in Great Britain 



mali 1 Allerch., Myxosporiwn mali 2 Bresadola and Alternaria grossularieae 

 Jacz 3 . 



Others whose identity could not be determined were regarded as 

 separate fungi from the fact that the general characteristics remained 

 fairly constant in successive sub-cultures. They were transferred to 

 potato mush agar in the autumn of 1918 and in the majority of cases 

 reproductive bodies were formed. These fungi 4 include: 



(a) Species of a phomoid genus differing from Phoma in possessing 

 compound, unilocular pycnidia with multiple necks, to which the name 

 Polyopeus 5 is given — P. purpureus, P. pomi, P. recurvatus and P. aureus. 



(b) An aggregate species of Fuckelia — F. botryoidea. 



(c) A species of Coniothyrium with lobed pycnidia — C. convolutum, 

 and a form of C. cydoniae. 



(d) A species of Alternaria forming in media "pockets" of conidia 

 — A. pomicola. 



(e) A species of Pleospora — P. pomorum, with a dematiaceous 

 stage of the Stemphylium pyriforme type. The identity of the conidial 

 and ascigerous stages has been proved by reciprocal single spore cultures. 



(/) A species of Sclerotium — S. stellatum, somewhat resembling 

 S. bataticolum 6 . 



Three other fungi have not yet formed reproductive bodies rendering 

 identification impossible; they are: 



(a) The thick-walled fungus to which reference has been made. 



(b) A slow-growing fungus presenting a dingy white and somewhat 

 powdery appearance at the surface of the medium when grown on apple 

 agar. This fungus was obtained 21 times from spots, with a centrally 

 situated lenticel, varying in size from ^ to | in. in diameter. 



(c) A sterile fungus, isolated from Ben's Bed and King of Tomkins 

 County, producing brilliant colours when grown on different media. On 

 apple agar the colours vary from dull pink to bright orange-yellow; 

 on potato slants they vary from pink to yellow, yellow-green with a 



1 See Allescher. Ber. Bot. Ver. Landshut. xii, p. 130 (1892); and Oudemans, Cat. 

 Champ. Pays Bas, p. 531. 



2 See Bresadola. Hedwigia, p. 382 (1897). 



3 This aj>ple Alternaria proved morphologically identical with Alternaria grossularieae 

 (Jaczewsky, Bull. Soc. Myc. Fr. xxn, 1906, p. 122), isolated by one of us from gooseberries. 



4 For descriptions of the new species see the Journal of Botany, vol. lviii, p. 239. 

 (Oct. 1920). 



5 The morphological and physiological characteristics of this genus will be described 

 elsewhere, 



6 Tubenhaus, J. J. Phyt. in (1913), p. 164; also Martin, William H. Phyl. vn (1917), 

 p. 308. 



