358 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the fungus by affording suitable conditions for the germination of the 

 spores. It also grows in the jungle on bushes of various kinds. 



In a more recent paper* Petch describes another disease of Hevea, 

 called "die-back." The fungus which begins the disease is Glo&o&porium 

 alborubrum Petch, and it attacks the young shoots. The further stage 

 of the die-back is a wound parasite Botryodiptlodia elasticse ; it does not 

 enter the tree until the top-shoots have been killed by the Glaiosporium, 

 but it does far more damage. When trees are attacked, the diseased 

 tops should be at once cut off and burnt, and the cut surface tarred. 



The stem-bleeding disease of the coconut f has also been investigated 

 by Petch. He found that it was due to a fungus, Thielaviopsis 

 ethaceticus, which causes the bark to split, and from the wounds thus 

 made the sap flows out. The progress of the disease is very slow, and 

 the tree is gradually hollowed out by the action of the fungus. Petch 

 recommends cutting out the diseased patches and tarring the wound. 



A disease broke out in a field of celery % in Sussex in 1909 and 

 caused considerable loss : it was caused by a fungus Phyllosticta Apii • 

 the black perithecia containing countless minute spores are produced on 

 blackened spots of the leaves. The disease spreads with great rapidity 

 in damp dull weather. A second disease caused by an allied fungus, 

 Septoria Petroselini, has been known for some time. The leaf spots are 

 smaller, and the spores needle-shaped. The latter disease also spreads 

 with great rapidity. The same preventive measures are recommended 

 for both, viz., spraying with half -strength Bordeaux mixture. 



Brown rot of tomatoes § has also been dealt with by the Board of 

 Agriculture. The fruit only is attacked : it shows discoloured patches, 

 and the skin and the pulp become reduced to a dark-coloured mass ; 

 the seeds are also brown in colour, and contain fungal hyphaa which 

 resemble the hyphas of Phytophthora omnivora. The brown seeds 

 germinate, and are reported to produce plants which bear infected fruits. 



F. J. Seaver || publishes a popular account of plant diseases in a 

 lecture delivered by him in New York Botanical Gardens. Most of the 

 diseases treated are due to fungal parasites belonging to Ustilagineaj, 

 Uredinese, and Ascomycetes. He also touches on gall-formation by 

 insects, and on the harm done to cultivated plants by dodder. 



Bach man, Frida M. — Discomycetes in the Vicinity of Oxford, Ohio. 



Proc. Ohio State Acad. Set., v. No. 2 (1909) pp. 19-70 (4 pis.). 



Britzel mayer, M.— Revision der Diagnosen zu den von M. Britzehnayer auf- 

 gestellten Hymenomycetenarten. (Revision of the diagnoses of Britzehnayer's 

 new species of Hymenomycetes.) 



Beih. Bot. Centralbl., xxvi. (1910) pp. 205-25. 



Krieger, W. — Fungi saxonici, Nos. 2051-2100. 



[Notes on locality and substratum, along with diagnoses of new species, are 

 given.] Konigstein, in Saxony, 1909. 



See also Bot. Centralbl., cxiii. (1910) p. 198. 



* Circ. and Agric. Journ. Roy. Bot. Gard. Ceylon, iv. No. 23 (1910) pp. 307-21. 



t Op. cit., No. 22 (1909) pp. 197-305. 



J Journ. Board Agric, xvi. (1910) pp. 1010-11 (G figs.). 



§ Tom. cit., p. 1012. 



|| Journ. New York Bot. Gard., x. (1909) pp. 241-56 (5 figs.). 



