ABSTRACTS. 



925 



in twenty days, about the middle of December ; the plants died down, 

 having already formed strong tubers the size of a large nut, which gave 

 plants rapidly in the spring. Though probably known to specialists 

 already, this procedure is recommended for general adoption with 

 novelties.— C. T. D. 



Dahlias, Cactus, on Wired Walls. By Ch. Gr. {Bev. Hort. p. 491 ; 

 November 1901). — Description of north wall so covered, permitting the 

 better display of the flowers, which, in the bush form, are often hidden. 



C. T. D. 



Dahlias, New Types. By H. Dauthenay {Bev. Hort. pp. 494-5 ; 

 November 1901). — Description of new sport d collerette (' Gloire de 

 Nancy '), in which a circle of undulate white petals surrounds the central 

 disc of yellow florets, large petals of deep red or purple, slightly margined 

 with w^hite, forming the outer corolla. Raised by M. Gerbeaux, Nancy. 



C. T. D. 



Date Palm, Culture of the. By Dr. Georg Schweinfurth 

 {Gartenflora, pp. 506-517 and 541-546; 15/10/1901). — A comprehensive 

 paper dealing with the cultivation of the Date Palm. 



A similar account is given by Mr. W. T. Swingle in the Year Book 

 of the U.S. Dep. Agr. 1900.—/. P. 



Deciduous Trees in Tropical Primitive Forests. By G. Scheffler 

 (Not. Konig. Bot. Berlin, No. 27, p. 139, Oct. 1901).— Under the title 

 Ueber die Beschaffenheit des Usamhara-Uriv aides, &c., the author gives 

 an interesting series of natural-history notes on the habits, general 

 characters, and especially the alternations of leaf-fall and leaf-flushes of 

 trees in a region purely tropical. Usambara is in German East Africa, 

 and only about five degrees south of the Equator. He divides the trees 

 into three groups : (1) Those which hardly ever show signs of leaf-strip- 

 ping, and are as nearly "evergreen" as a plant can be; (2) a series 

 which during a certain period are distinctly prone to shed most of their 

 leaves ; and (3) a series which are entirely or nearly bare of leaves during 

 a certain season of the year. The chief interest of the paper lies, in our 

 opinion, less in the confirmation of the fact, already known to botanists, 

 that so-called evergreen forests are not and never can be strictly such — 

 though the author adds many definite cases to the list — than in the inter- 

 esting little notes about such points as the period of flowering, the pecu- 

 liarities of the wood, &c., of several strange and little-known trees. Such 

 natural-history notes made on the spot are of great value and far too rare 

 to be under-estimated. — H. M. \V. 



Dendrobium barbatulum, Lindl. (Cogniaux in Diet. Icon. Orch., 

 Dendr., pi. 25 ; 5/1901). — A native of India, introduced in 1844. Flowers 

 numerous, pure white. — C. C. H. 



Dendrobium Hookerianum, Lindl. (L. Linden in Lind. xvi. 

 pi, 730 ; 1/3/1901). — A rare and beautiful species introduced from Assam 

 in 1868, though originally discovered by Sir Joseph Hooker in Sikkim in 

 1848. Flowers deep golden yellow, with two maroon blotches at base of 

 lip, column white. — C. C. H. 



