750 SUMMARY OF CURRENT RESEARCHES RELATING TO 



due to a fungus, Ulosporium malifoliorum ; it forms characteristic Leaf- 

 blotches. 



P. Bacarini* has described a parasitic fungus, Botrytis Pistiir sp. n., 

 that attacks and destroys the leaves of Pistia stratiotes at the end of the 

 summer. The conidial form alone was observed ; a diagnosis is given. 



K. Kornauth and G. Kockf give an account of the gooseberry 

 mildew in Austria, where it has spread very largely. They describe the 

 difference between the American and European mildews on Ribes, and 

 suggest remedies. 



Griffon and MaublancJ have published a note on the very serious 

 mildew of oaks. Specimens of affected leaves have been received this 

 last season from all over France, though it was scarcely known until the 

 previous year. The suggestion is that it is an indigenous species, 

 Microsphcera Alni, that has suddenly attacked a new host ; on the other 

 hand, it may be an exotic form of the same fungus that has been intro- 

 duced. (It has also recently appeared in England.) 



Ed. Bureau § writes in a later issue of the same journal an account 

 of the disease as he has observed it. In some of the woods the whole 

 of the oak leaves had become grey and hung down, recalling the foliage 

 of the Australian Eucalyptus. He made an examination of the oaks 

 attacked, and found that while in Quercus pidunculata and others the 

 whole of the leaves were attacked, in Q. sessiliflora only the young 

 shoots suffered. Q. rubra, a North American species, was similarly 

 affected, only the young shoots being mildewed. The beech has also 

 been attacked by the same mildew, but only the young* shoots, and 

 usually only in hedges, the forest trees having escaped. The chestnut 

 is immune, and so also is Q. suber, the cork oak. 



E. S. Salmon || records a disease on cherry trees caused by Exoascus 

 minor, which is not to be confounded with E. cerasi. The former 

 attacks the young wood, and the mycelium persists during the winter. 

 Judicious removal of the twigs affected will soon stamp out the disease. 



A disease of coconut palm in Travancore has been investigated by 

 E. J. Butler. f It showed itself by withering of the leaves and the bud, 

 finally the crown falls off. The tree does not die at once, but few nuts 

 are produced, and these few do not ripen. A parasitic fungus on the 

 roots was probably the cause of the evil. Infection experiments are 

 proposed. 



A stem disease of the same palm, called " bleeding disease," has 

 been found by T. Petch** to be probably due to the fungus ThMaviopsis 

 ethacvtinis, as it is always present on the diseased tissue. Cutting out 

 the injured parts, scorching and sterilising with hot tar, have given good 

 results in stamping out the disease. 



* Bull. Soc. Bot. Ital., 1908, pp. 30-1. 



t Monats. Landw., 1908, p. 50. See also Bot. Centralbl., cviii. (1908) pp. 

 179-80. 



J Comptes Bendus, cxlvii. (1908) pp. 437-9. § Tom. cit., pp. 571-4. 



|| Gard. Cbron., xliii. (1908) pp. 209-10. 



1 Agric. Bes. Inst. Pusa, Bull. 9, 23 pp., Calcutta,1908. See also Bot. Ceutralbl. 

 cviii. (1908) p. 299. 



** Agric. Journ. Boy. Bot. Gard. Ceylon, iv. (1907) pp. 49-53. See also Bot. 

 Centralbl. cviii. (1908) p. 303. 



