NOTES AND ABSTRACTS. 
489 
Cucumbers, The Control of Bacterial Wilt of.^ By F. V. Rand and E. M. A. 
Enlows {Jour. Agr. Res. vol. vi. No. 11, June 1916, pp. 417-434; 2 plates). — 
The experiments show that cucumber beetles {Diabrotica spp.) are the most 
important of the summer carriers of the wilt organism {Bacillus tracheiphilus), 
and that the beetle {Diabrotica vittata) is capable of carrying the wilt over 
winter and infecting the spring seedlings of cucumbers. It is also proved that 
the twelve-spotted cucumber beetle {Diabrotica duodecimpunctata) can carry 
the disease. It is therefore necessary to devise methods of control for these 
insects in order to prevent the disease. — A. B. 
Cucurbits, Dissemination of Bacterial Wilt. By F. V. Rand (Jour. Agr. 
Res. v. p. 257, Nov. 1 91 5 ; pi.). — The beetle Diabrotica vittata has been regarded 
as the agent in disseminating the bacillus of cucumber wilt disease {Bacillus 
tracheiphilus) from plant to plant in summer. The author shows by a series 
of experiments that the hibernating beetles which have fed on wilted cucumbers 
are capable of carrying the disease over winter and infecting fresh plants in the 
next season. — F. J. C. 
Cupressus thyoides. By A. Bruce Jackson {Gard. Chron. Aug. 19, I9i6,p. 85 ; 
with 2 figs.). — The fifteenth of this series of notes on conifers. This Ameri- 
can species is not happy in English gardens, and few specimens are known. 
A shrubby form is known as var. leptoclada. — E. A. B. 
Cytisus ratisbonensis {Bot. Mag. t. 8661). — Siberia to Central Europe. Nat. 
Ord. Leguminosae, tribe Genisteae. A small shrub. Leaflets | inch long. In- 
florescence in long racemose sprays, 6 inches long. Corolla § inch long, yellow. 
G.H. 
Cytisus sp. (Les Cytises Fourragers). By G. V. Perez {Bull. Soc. nat. d'Acclim. 
de Fy. vi. June 1916). — Deals with ' Tagasete ' {Cytisus proliferus var. 
palmensis Christ), ' Gacia ' (C. madevensis Masf.), and ' la Herdanera ' or ' Gacia 
blanca ' (C. pallidus Poir. = Genista splendens W. et B.), and the identification 
of these plants mentioned in ancient writings. — F. J. C, 
Dahlia, Introduction of, into England. By C. Harman Payne {Gard. Chron. 
Sept. 23, 1916, p. 143). — Provides evidence that the Dahlia was introduced 
to England by means of seeds obtained by the first Marchioness of Bute from 
Dr. Ortega, Director of the Madrid Botanical Garden, and grown at Kew in 1798, 
and that the accepted date of 1789 is due to a printer's error (see p. 305). 
E. A. B. 
Dahlia, Origin of Pompon. By C. Harman Payne {Gard. Chron. Sept. 2, 9, and 16, 
1916, pp. 107, 119, and 133; with 2 figs.). — A careful review of negative and 
positive evidence from old Dahlia literature, leading to the conclusion that the 
Pompon Dahlia was not raised, as has been stated, by Hartweg of Carlsruhe from 
D. coccinea in 1808, but more probably originated in Germany in the middle of 
the nineteenth century. — E. A. B. 
Dahlias, Classification of. By F. Cayeux {Rev. Hort. April 16, 191 6). By 
Antoine Rivoire {Rev. Hort. May 16, 1916). — Two interesting articles on this 
subject, treating of the several distinct classes into which the Dahlia has diverged. 
C. T. D. 
Diseases, Plant, Grouping and Terminology of. By L. E. Melchers {Phyto- 
pathology, v. pp. 297-302 ; Nov. 1915). — The author proposes a distribution 
of plant diseases into the following groups : (1) Non-parasitic diseases, including 
{a) Exanthema, bitter-pit, lightning injury, leaf scorch, sun scalds, &c. ; {b) 
Autopathogenic diseases, including leaf -roll of potato, chlorosis, cedema, blossom- 
end rot of tomato, brachysm of cotton, &c. (2) Diseases of unknown origin, 
including mosaic disease, peach yellows, little peach, curlytop of beets, straight 
head of rice, oat blast (thrips ?) &c. (3) Parasitic diseases, including all diseases 
caused by fungus or bacterial organisms. Notes are given on each group. 
F. J. C. 
Drug and Dye Plants, Report on Cultivation. By H. H. Rusby {Jour. 
New York Bot. Gard. xvi. pp. 155-172, Aug. 1915). — The committee reporting 
considers that those who engage in the work of growing drug and dye plants 
should be assured that (1 ) there is a steady and sufficient demand for the product ; 
(2) soil and climate are adapted to its growth ; (3) they are sufficiently familiar 
with its individual requirements to grow it successfully ; and (4) the market price 
will leave a margin over the cost of production and marketing. Success in 
