ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 289 



twigs which became virulently attacked by the mildew. Early removal 

 of shoots and berries attacked is essential, and finally spraying with 

 lime-sulphur as a valuable aid. The names of the varieties of goose- 

 berry not easily damaged by sprays are supplied, and information is 

 given as to the best seasons for pruning, spraying, etc. 



Plant Diseases.* — A disease of narcissus bulbs has been described 

 by Gr. Massee. It occurred in this country about three years ago and 

 did very serious damage. The injury is due to the fungus Fusarium 

 lulbigenum, first described in 1887, though not then recognized as a 

 destructive parasite. The presence of the fungus is first indicated by 

 the appearance of small yellowish spots on the leaves, which gradually 

 increase in size and become brown and dry. On these spots small 

 coloured patches of Fusarium spores are developed ; they are dispersed 

 by various means and infect other plants. The mycelium within the 

 leaf can be traced passing downwards into the bulb, where it grows with 

 great vigour in the fleshy scales. In time the whole bulb becomes 

 diseased, the fungus forming delicate white sheets of mycelium between 

 the scales. Massee describes two forms of spores : the characteristic 

 elongate septate spores of Fusarium, which are borne in clusters at the 

 tips of the hyphse, and small globose chlamydospores or resting spores 

 which are abundant in the leaf -tissues. It is recommended to avoid 

 planting bulbs in infected soil. 



An account of the ravages of wart-disease of potatoes! has been 

 contributed by J. Eriksson. Researches and experiments have demon- 

 strated that the disease spreads slowly but steadily ; and the contagious 

 matter preserves its virulence in the soil for years ; fungicides having 

 proved ineffectual in preventing or even diminishing the mischief. A 

 list is given of varieties of potatoes that are immune or partially immune 

 to the disease, and of those that are non-resistant. 



An account is also given of the treatment of soil in Sweden with 

 1 p.c. formalin solution. The experiment proved that in soil recently 

 infected the fungus may be destroyed. In soil which has harboured 

 the fungus for years a much stronger solution (2 or 3 p.c.) is necessary 

 to have any effect. 



H. Zimmerman J records the damage done to cherries by the fungus 

 Fusicladium Gerasi, a rather rare parasite. Certain kinds of fruit only 

 were attacked, but experiment is required to determine accurately the 

 degree and conditions of immunity. The writer strongly urges the 

 gathering and destroying of all diseased cherries. 



Himmelbauer § has made a special study of Fusarium as the cause 

 of the infolding of potato leaves. His aim was to discover in how far 

 the plants became infected in the soil. It is only when pathogenic 

 forms of Fusarium are present that there is any danger. When the 



* Journ. Board. Agric, xx. (1914) pp. 1091-3 (1 pi.). 



t Int. Inst. Agric. Bur. Agric. Int. and PL Dis. Rome, 1914, pp. 276-8. 



X Bl. Obst.-Wein Gart. Bau (1913) p. 107. See also Bot. CentralbL, cxxv. 

 (1914) p. 143. 



§ Oest. Zeitschr. Zuckerind. Landw., xlii. 5 (1913). See also Bot. Centralbl 

 cxxv. (1914) p. 141. 



