620 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ing hot and moist conditions favour their development. Magnus gives 

 a list of those that have been found in that region. 



Arthur S. Home * has been studying a potato disease known as 

 " Internal Disease." He finds that it is due to an organism in the 

 host-cell, a small vesicle attached to the wall of the cell. The vesicle 

 increases in size and gives rise to one or more spheres which bud off 

 sporangia ; finally, spores are formed, which give rise to exceedingly 

 small swarm-spores. Home suggests that it be regarded as a Chytri- 

 diaceous fungus of generic rank, standing near the Olpidiaceee and 

 Synchytriacese. 



A tomato disease f new to England is caused by the fungus Septoria 

 Lycopersici var. europsea. The leaves of the plant are attacked first and 

 rapidly killed, then stem and fruit. A crop of outdoor tomatoes was 

 destroyed by it in Gloucestershire in 1907, and it reappeared in 1908. 

 Instructions are given for dealing with the disease. 



L. Petri J describes the drying up of olive leaves due to the presence 

 of the parasitic fungus Phyllosticta insulana. It destroys the leaves, and 

 is capable of causing very great loss. Petri notes the points of difference 

 between this and other parasites of olive-leaves. 



A disease § termed apple blotch has been doing great harm in the 

 orchards of the southern United States. W. M. Scott and James B. 

 Rorer have made a study of the fungus, Phyllosticta solitaria, that causes 

 the disease. It may occur on leaves, branches, or fruits : on the latter 

 it causes cracks and splits, and seriously lessens the value of the apples ; 

 the fungus seems to persist on the branches. Spraying with Bordeaux 

 mixture is recommended. 



The Board of Agriculture || takes note of the disease of gooseberry 

 bushes caused by Puccinia Prinysheimiana — it has been apparently more 

 prevalent this year than usual. Two cases of disease due to coral spot 

 (Nectria cinnabarina) are reported ; apricot stems and gooseberry bushes 

 were both fatally injured. Potatoes from Montrose were attacked by 

 Rhizoctonia violacea ; others from Manchester were injured by dry-scab, 

 Spondyloeladium atrovirens. 



Em. Marchal % examined the deformed fruits of a pear, and found 

 that they had been attacked by Phytophthora omnivora : the fallen fruits 

 were found to be filled with the oospores of the fungus. These fruits 

 should be carefully destroyed, and the trees sprayed with Bordeaux 

 mixture. 



E. Paque ** gives a sketch of the history of the oak mildew in Europe. 

 He describes the appearance of the fungus, and discusses at some length 

 its systematic position. He is certain that the species is indigenous, that 

 the recent outbreak is due to special atmospheric conditions, and that 

 there is no need to be alarmed about the spread of the disease. 



* Ann. Mycol., vii. (1909) pp. 286-8. 

 t Board of Agric. Leaflet 225 (1909) 3 pp. (5 figs.). 

 X Atti Reale Accad. Lincei, cccvi. (1909) pp. 620-3 (2 figs.). 

 § U.S. Dep. Agric. Bureau PI. Ind., Bull. No. 141 (1909) 23 pp. (6 pis.). See 

 also Ann. Mycol., vii. (1909) pp. 308-9. 



|| Journ. Board. Agric, xvi. (1909) p. 297. 

 \ Bull. Soc. Roy. Bot. Belg., xlv. (1908) pp. 343-4. 

 ** Tom. cit., pp. 344-54. 



