NOTES AND ABSTRACTS. 



321 



agents, such as plant lice and the tarnished plant bug, which does 

 considerable damage, also the removal of all sources of infection, are 

 necessary. Trees and nursery stock should be frequently inspected, 

 as often as two to three times weekly, and any diseased portions 

 pruned away and the cut disinfected with i/iooo corrosive sublimate. 

 Fire blight is one of the most destructive diseases with which American 

 fruit-growers and nurserymen have to deal. It was first observed as 

 early as 1780 in the Hudson River highlands of New York State, and 

 it is now found throughout the United States and Canada. 



The author of this circular describes the symptoms and spread of 

 the disease in great detail. — D. M. C. 



Fire Blight Disease in Nursery Stock. By V. B. Stewart 

 (U.S.A. Exp. Stn., Cornell, Bull. 329, April 1913 ; figs.). — Fire 

 blight due to Bacillus amylovorus is widely spread in America. The 

 symptoms have already been detailed in earlier abstracts. They are 

 reviewed in the present publication, the organism is re-described, 

 its life-cycle and modes of dissemination are detailed, and the import- 

 ance of seeing that nursery stock is free from the disease is emphasized. 

 Pear, apple, quince, apricot, plum, species of Crataegus, Amelanchier 

 canadensis, Pyrus americana and some other Anlerican species of 

 Pyrus, Eriobotrya japonica, and Heteromeles arhutifolia growing in the 

 neighbourhood of orchards are all known to be liable to attack. 



F. J. C. 



Fires on Standing Hardwood Timber, Effect of Forest. 

 By W. H. Long [U.S.A. Dep. Agr., For. Serv.,Circ. 216, March 31, 1913). 

 — One of the most injurious effects of small forest fires is the killing 

 of the young growth and the destruction of the layer of leaves and 

 mulch on the ground which protects the soil during heavy rain. 



A. D. W. 



Flowers, Biology of European. By Rob. Stager (Beih. Bot. 

 Cent. xxxi. Abt. 2, Heft 2, pp. 281-321). — The pollination of the 

 following flowers is described in detail : — 



Colchicum alpinum, Gagea Liottardi, Allium victoriale, A. Schoeno- 

 prasum, Lilium croceum. Crocus vernus, Castanea sativa, Thesium 

 alpinum, Dianthus inodorus, D. vaginatus, Cerastium trigynum, Alsine 

 sedoides, Anemone alpina. Ranunculus parnassif otitis, Papaver Lecoquii, 

 Biscutella laevigata, Hugueninia tanacetijolia, Hutchinsia alpina, 

 Capsella, Draba, Arabis, Sedum (4 species), Saxifraga (3 species), 

 Lieversia (2), Geranium columbinum, Linum (2 species), Viola cenisia, 

 Epilobium alsinifolium, Loisetetma, Androsace (2), Gentiana (2), 

 Convolvulus (2), Myosotis alpestris, Veronica alpina, and two others, 

 Erinus and Campanula (7 species). 



The author counted the number of flowers in a square space 

 measuring 90 centimetres each way. 



In one place, Col d'Emanay, 2100 metres alt., he found 1716 single 

 flowers in this area of which there were 1280 flowers of Myosotis alpestris 

 alone ; on the Salampe Alp, 1950 metres Unterwallis, on stony soil, 



