UROPHLYCTIS 95 



remedy against the infection of future crops is one which is 

 scarcely practicable, that of removing every infected root 

 from the soil and burning them. 



Even if this were done there is the risk of fragments of 

 diseased portions remaining. As the disease appears to be 

 confined to leguminous plants, no such crops should be 

 grown on land bearing a diseased crop for some years. 



Salmon, South- Eastern Agric. Coll., Wye. July (1907). 



Carum leaf-galls. Magnus has described galls found on 

 Carum carvi, C.persicum, and Pimpinella magna by Urophlyciis 

 Kriegeriana (P. Magnus). The galls are small and pearl-like 

 and occur on the surface of the leaves, stem, and floral parts. 

 Adjoining cells often fuse more or less completely and form 

 hyaline punctate crusts, especially on the stem. Each gall 

 has a slight depression at its apex, which leads into a very 

 large cell in the middle of the gall. The fungus is confined 

 to this cavity. The formation of a gall is caused by a germ 

 of the parasite entering an epidermal cell, which in conse- 

 quence swells considerably and causes repeated division of 

 neighbouring cells, forming a thick wall round the central 

 enlarged cell, and leaving an opening at the apex. The 

 membrane at the apex of the gall is traversed by a filament 

 of mycelium which dilates into a vesicle, from which other 

 hyphae originate. This process is repeated until a quantity 

 of hyphae are produced, which eventually produce conjugat- 

 ing cells. Male and female conjugating cells arise respec- 

 tively from distinct sets of hyphae. At first the conjugating 

 cells are of nearly equal size, soon, however, some increase 

 considerably in size, while others remain small the male 

 cells and the contents of a smaller cell pass through a 

 connecting tube into a larger cell. The female cell, after 

 conjugation, continues to enlarge, and forms a thick, dark 

 brown wall. On the side where conjugation takes place, the 

 cell remains flat and somewhat depressed at the centre. The 

 presence of zoosporangia has not been observed in this 

 species. 



Magnus, P., Sitzungsh. Gesell. Natur-Freunde, Berlin 

 (1888), p 100. 



Magnus, P., Ann. Bot., 11, p. 87 (1897). 



Beetroot tumour. This is caused by Urophlyciis leproides 



