ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 



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the Hudson River Yalley attack, and has found it due to the same 

 fungus. That F. oxysporum is the primary cause of the disease is shown 

 by the constant association of the fungus with the potato, and has been 

 proved convincingly by artificial cultures and inoculation. It causes 

 necrosis of the tubers ; the plants arising from such tubers are weak 

 and the yield is small. The writer has examined also its relation to 

 temperature : it develops best in hot weather. The suggestion is made 

 that early potatoes that mature before the great heats should be grown 

 in districts liable to the disease. A. L. S. 



Philippine Plant Diseases.— Otto Reinkino, the autlior of this 

 ^di-^Qv {Phytopathology, 1919, 9, 114-40), states that fungus diseases 

 are found on practically all cultivated and wild plants in Laguna Pro- 

 vince, Island of Lugon. The long series of forms that he describes 

 occur mostly on economic plants, and are described under their respec- 

 tive hosts, alphabetically arranged from Ananas sativus (pineapple) to 

 Zea Mays (corn maize). In most cases information is given as to the 

 remedies used and the results obtained. 



In Sinother i>aper {Philipp. Jo urn. Sci, 1918, 13, 165-274, 2 pis., 

 43 figs.) the author treats the subject in detail. He gives an alpha- 

 betical list of hosts and parasites with the method of treatment suitable 

 in each case. The list is a long one, as according to Reinking plant 

 diseases are peculiarly abundant in the islands. There are, he says, 

 more plant diseases there than in the whole United States. A. L. S. 



Leaf-spot Disease of Red Clover caused by Macrosporium sar- 

 cinaeforme. — The author of this paper, L. J. Keakover {Nineteeyith 

 Report, Mich. Acad. Sci., 1917, 275-328, 5 pis.), draws attention to the 

 diseases of red clover which he says have been very little studied. He 

 gives an historical sketch of the occurrence of leaf -spot from its first 

 recognition by Cavara in Italy in 1890. The disease is very widely 

 distributed and is very destructive ; it attacks both the leaves and the 

 petioles. Krakover was able to observe that infection took place by the 

 germinating tube piercing the leaf between the epidermal cells ; it then 

 attacks the parenchyma, which is finally killed and invaded. The fungus 

 then sends up hyphae through the stomata or between the epidermal 

 cells on both sides of the leaf, and these bear spores at the tips, of the 

 well-known Macrosporium type. The author made many culture and 

 infection experiments, all of which are described in detail. He found 

 that it grew well on a large variety of culture media without striking 

 modifications. Finally, he recommends the breeding of resistant varieties 

 of clover as the only method of combating the disease. The paper is 

 well illustrated. A. L. S. 



Disease of Flax Seedlings. — A disease known in the North of 

 Ireland as " yellowing " has been investigated by G. E. Pethybridge 

 and H. A. Lafferty {Sci. Froc. Roy. Dublin Soc, 1918, 15, 359-84, 

 2 pis.). The fungus causes spots on the leaves and lesions on the 

 stems somewhat resembling " damping off." A species of Colletotrichum 

 was found associated with the injury, and infection experiments proved 



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