NOTES AND ABSTRACTS. 



641 



in the centre, the latter forming the " collerette." Sent out by Vilmorin 

 and regarded as the commencement of a distinct type. — C. T. D. 



Date-leaf Boat. Anon. (Gard. Chron. No. 854, p. 800 ; May 9, 

 1903). — A description of certain boats which are used in the Persian Gulf 

 is given by Dr. Fairchild in the 'Botanical Gazette.' They are made 

 entirely of the midribs of the leaves of the Date Palm, strips of which are 

 cut about H inch in diameter and 10 feet long. They are fastened 

 together with wooden pegs and strong twine. The coast is so barren that 

 it is impossible to get wood, the only trees being a few Date Palms planted 

 round the telegraph station at Jask. — G. S. S. 



Davidia involucrata. By M. T. Masters (Gard. Chron. No. 850, 

 p. 236, fig. 98 ; April 11, 1903).— This fine plant is a native of China ; it 

 was first discovered by the Abbe David in 1871, and has been for some 

 little time under cultivation in France, but it has only lately been intro- 

 duced into commerce. " We doubt not that so showy a species will 

 speedily become common." In growth it much resembles a small Lime- 

 tree. The two bracts below the flowers are large, and cream-coloured, 

 flushed with pink. If it proves hardy and flowers freely in this country 

 it will be a great acquisition to our gardens. — G. S. S. 



Davidia involucrata, The Germination of the Seeds of. By 



W. B. Hemsley (Joum. Linn. Soc, Bot. vol. xxxv. p. 556, pi. 19). — 

 " Davidia is one of the most remarkable of the endemic genera of the 

 trees of China. It is a monotype, with foliage strongly resembling that of 

 a Lime-tree, and an inflorescence resembling no other." The fruit is oval 

 and about 1^ inch in length. When the outer part decays the carpels 

 partly open, the seeds germinate, and " the radicles of as many seeds as 

 are present in the fruit emerge simultaneously." There is also a rapid 

 elongation of the cotyledons, by which the axis of the plantlet is carried 

 outside of the testa, the radicles turn towards the soil, which they enter 

 when the developing cotyledons absorb the reserve-materials of the endo- 

 sperm, soon free themselves and assume a horizontal position, become 

 green, and persist a long time. — G. S. S. 



Dendrobium Harveyanum (Orch. Rev. Oct. 1903, p. 313, 

 fig. 48). — A finely illustrated raceme of four flowers is given in the 

 photographic reproduction. Particulars of its history are also included. 



H. J. C. 



Dendrobium Madonnse. By Sir J. D. Hooker (Bot. Mag. tab. 

 7900).— Nat. ord. Orchidece, tribe Dendrobica. Native of New Guinea. 

 The flowers are 2^ inches broad, nodding, white, with a few purple spots 

 near the margins of the lateral lobes of the lip.— G. H. 



Denitrifieation, Contributions to the Morphology and Physio- 

 logy Of. By J. G. Lipman (U.S.A. Exp. Stn. New Jersey, Rep. 1902 ; 

 pp. 183-241 ; one plate). — The changes brought about in dead organic 

 matter by certain kinds of bacteria frequently lead to very considerable 

 losses of nitrogen. The factors determining the extent of this loss are : 



