2G4 JOURNAL OF THE KOYAl. HORTICULTURAL SOCIETY. 



Delphinium Ajacis and J), cousolida, and they comprise a series of very 

 distinct forms, severally known as dwarf, rocket, branching, candelabrum, 

 hyacinth-flowered, stock-flowered, and the ranunculus-flowered. These 

 are all worth cultivating, but for general purposes the best are the 

 branching, the hyacinth-flowered, and the rocket, which may be had in all 

 colours except shades of yellow, of which the genus Delphhmim gives no 

 examples, unless we recognise D. ochrolcuciim as a yellow, which, properly 

 speaking, it is not. The annual larkspurs are among the gayest flowers 

 of their class, and the bright blue varieties are very beautiful. The 

 larkspurs make finer spikes of flowers and last much longer when the 

 seed is sown in autumn, and this practice provides the garden with 

 agreeable verdure through the winter, for ^le plant is quite hardy, and 

 fine clumps often appear from self-sown seeds.— i/. T. C. 



Lettuce : American Varieties of. By W. W. Tracy {U.S.A. Dep. 

 Agr., Bar. PI. Lid., Bull. 68 ; Dec. 1904 ; 27 plates).— The American 

 Department of Agriculture has determined to study, and after a careful 

 series of trials to publish the results, with descriptions and synonyms, 

 the various kinds of vegetables one by one, the main idea being to apply 

 to a horticultural subject the methods of systematic botany. Trials were 

 conducted with 2,934 samples under 444 dift'erent varietal names, and it 

 is considered that these are reducible to 107 varieties, the remainder of 

 the names being merely synonyms. These are described, notes on history 

 and culture are given, and where necessary illustrations (photographic) 

 are given. The descriptive terms used are defined w'ith precision, and 

 an outline of classification intended to show the relationship of the 

 varieties is given, together with a dichotomous key which greatly facili- 

 tates the identification of varieties. — F. J. C. 



Lettuce **Drop" Disease. By H. J. Eamsey Exp. Stn. 



Wisconsin, Ann. Bep. 1904, pp. 279-288 ; 2 figs.).— Great difiiculty is 

 experienced in growing lettuce in greenhouses owdng to the presence of a 

 fungus {Botrytis). The first symptom of the disease was a burning at 

 the tip of the leaves followed by a partial drying-up of the leaf which 

 became of a buft'-brown colour. At this stage hyphte were to be 

 found in the tissues ; later the watery stage of decay set in and the 

 leaves became limp and flabby and the spores of the fungus were pro- 

 duced in abundance. In the particular case under observation all infection 

 seemed to come from air-borne spores, and no sclerotia were formed in 

 the attacked plants. Burning sulphur in the house resulted in injury to 

 the plants and did not stop the spread of the fungus. In a second case 

 infection came from sclerotia in the soil {Sclerotinia lihertina Fuckel), 

 and in this attack the infection was rapidly followed by the total collapse 

 of the plant. Cultures of the sclerotia and mycelium were made, but in 

 no case were spores produced. It is pointed out that great care in 

 watering is necessary, and attention must be paid to ventilation and 

 temperature to ensure good results. The Massachusetts Experimsnt 

 Station has shown that one of the most efficient methods of prevention of 

 disease lies in the complete sterilisation of the soil to at least three inches 

 deep.— F. J.C. 



