ZOOLOGY AND BOTANY. MICROSCOPY. ETC. 85 



that the grower may choose without difficulty tlie variety that is adapted 

 to special soils as well as being immune. The article is also issued as a 

 Food Production Leaflet, No. 21, by the Board of Agriculture. 



An account of phloem necrosis lias been published by H. H . Quanjer, '■ 

 assisted by Van der Lek and 0. Botjes. Potato-plants which were 

 affected showed the disease in the curling of the leaves ; the phloem 

 was found to be abnormal, the cell-walls being swollen and discoloured, 

 the injury being most marked in the older portions of the tissue near 

 the bast-fibres. The trouble could be traced from the leaf-midrib to the 

 underground parts of the stem near the seed-tuber. Xo specific organism 

 has been detected as the origin of the necrosis. 



A paper by Tan der Lek f gives the results of his investigations on 

 Rldzodonia violacea, a fungal disease of beet-root, carrot, etc. He has 

 proved by culture experiments that it is not identical with R. Solani. 

 In the cultures on artificial media a fine mycelium was produced, which 

 in time became purple ; minute sclerotia were found, but no definite 

 reproductive bodies were observed. 



A. Cendner J describes an attack on Mathiola vaUsiaca hj Sderotinia. 

 The effect of the fungus was to wither the inflorescences, the petals 

 changing from the normal violet colour to red, as if they had been acted 

 upon by an acid. Other Crucifers in the neighbourhood were similarly 

 affected. The disease was traced to a species of Sderotinia not hitherto 

 described ; small black sclerotia w-ere detected within the stems. 



A. Osterwalder § describes the fungus causing a disease of Raspberry 

 in Switzerland. It is due to an Ascomycete, DidymeUa applanata, which 

 attacks the young stems and branches, and is easily recognized by the 

 reddish-brown or purple patches of the diseased areas. 



V. B. Stewart \\ describes a leaf -disease of Kerria japonica, due to a 

 species of Cylindrosporium. He describes the development of the fungus, 

 with its effect on the leaf, in which it forms a mass of tissue or stroma. 

 The leaves turn yellow and fall prematurely ; there is no shot-hole effect ; 

 the twigs which are also affected become black. In the autumn the 

 stroma increases, and early in the spring the perfect fruiting-form 

 develops. Stewart has determined that it is an Ascomycete, belonging 

 to the Phacidiales, Coccomyces Kerrise sp. n. He also found on the leaf 

 small pycnidia-like spermogonia with minute spermatia. 



L. M. Masseylf describes a crown-canker disease of rose that has caused 

 great damage in the United States to plants grown under glass. Lesions 

 are formed just at the surface of the soil, and may extend several inches 

 up the stem. Massey has determined the fungus as Cylindrodadium 

 scoparium, only known hitherto as a saprophytic Hyphomjcete. Cultures 



* Meded. Nijks Hoog. Land-Luin-Bosch-bouwsch., x. (1916) 138 pp. (12 pis.). 

 (Dutch, with English translation.) 



t Meded. Nijks Hoog. Land-Luin-Bosch-bouwsch., xii. (1917) 112 pp. (9 pis.). 

 '(French translation.) 



X Bull. Soc. Bot. Geneve, ser. 2, ix. (1917) pp. 21-9 (3 figs.). See also Bull. 

 Agric. Intell. Rome, viii. (1917) p. 1198. 



§ Schweiz. Obst.-Garteubau-Zeit., No. 12 (1917) pp. 175-7 (1 fig.). See also 

 Bull. Agric. Intell. Rome, viii. (1917) p. 1199. 

 . 1! Phytopathology, vii. (1917) pp. 399-405 (7 figs.). 



il Phytopathology, vii. (1917) pp. 408-17 (3 figs.). 



