Arthur S. Hornk and Eleanor Violet Horne 201 



be retarded by storing at lower temperatures than those frequently 

 adopted. It is however eminently desirable to systematically disinfect 

 the fruit-room since some of the fungi enumerated in this paper can grow 

 slowly and even sporulate at a comparatively low temperature (0°-5° C). 



7. Summary. 



This paper presents the results so far obtained in an investigation, 

 which has been carried on since 1915, into "spotting" in apples. The 

 symptoms of "spotting" as they are found and develop in numerous 

 varieties of apple are described. Several fungi have been isolated from 

 spots and cultured in various artificial media with the production of 

 spores. 



They include a new genus of Phomatales (Polyopeus) and nine new 

 species, of which at least one, Pleospora jjomorum, as the result of ex- 

 perimental inoculations, has been proved capable of parasitising apples. 

 The fungi do not include any of the species hitherto reported as causal 

 organisms in the United States, the only centre where investigations 

 into the "spotting" of apples, as distinct from the "bitter pit" problem, 

 has been undertaken. 



The work was commenced at the Wisley Gardens of the Royal 

 Horticultural Society. During the building of the Society's laboratory 

 it was continued, by the kindness of Professor V. H. Blackman, in the 

 Department of Plant Physiology and Pathology at the Imperial College 

 of Science and Technology. In was later carried on again at Wisley; 

 the work however has been completed at the Imperial College. 



The authors' thanks are due to Professor Blackman for his kind help 

 and criticism during the investigation. 



