468 BIBLIOOEAPnT. 



"Welwitsch, F.— Sur la Vegetation du Plateau de Huilla dang le 

 Benguela. Bibliotlieque Univ. July, 1861. Ext, 

 With observations by M. De Candolle. 



Extract fi-om a Letter, addressed to Sir William J. Hooker, 



on the Botany of Benguela, Mossamedes, &e. in Western Africa. 

 Linn. Proc. v. p. 182. 



Dr. Welwitscli notices the medley of species cidtivated at 

 Mossamedes (Little Fish Bay), Bananas and Potatoes, Man- 

 diocca and AVlieat, Sugar-cane and Elax, Hordeum distichum and 

 Batatas paniculata, &c. An extraordinary ti'ee of doubtful 

 affinity, growing on the table-land near Cape Negro, is described 

 in brief. It is said to attain 1 foot in height with a diameter 

 of 4 feet ; the pair of leaves thrown up at germination persist 

 through the lifetime of the tree, no others being produced. The 

 flowers are described as amentaceous, hexandrous, and mono- 

 gynous. A Bafflesiacea was found upon the branches of a Le- 

 guminosa. 



Wesmael, a. — Nouvel hybride de Girsiiim. Ac. Belg. 2 Nov. 1861. 

 Between C. arvense and C. lanceolatum. It is described in 

 much detail. 



White, E. B. W. — List of some of the rarer plants observed in the 

 \dcinity of Perth. Ti\ius. Ed. Bot. Soc. vii. 235. 



Botany of Methven, Perthshire. Phytol. 1861. 330. 



WiCKE, WiLii. — TIeber das Vorkommen und die physiologische 

 A^ei'wendung der Kieselsiiure bei den Dicotyledonen. Bot. Zeit. 

 1861. p. 97. 



WiESifEE, J. — Untersuchimgen iiber den Bogenwerth der Blatt- 

 basen, Sitzungsbericht. K. Ak. Wien. xlii. 1-17. 



WiGAND, A.— Beleuchtimg von Schacht's Behandlung der Erage 

 ■iiber die Intercellularsubstanz und die Cuticula. Flora, 1861, 

 pp. 81, 97. 



Ueber die Deorganisation der Pflanzenzelle, insbesondere 



iiber die physiologische Bedeutung von Grummi und Harz. 

 Pruigsh. Jalu'b. iii. 115. With 3 plates. 



The author is of opinion that gums frequently if not gene- 

 rally originate moi-e or less as Tragacanth, which has been shown 

 by von Mohl to result from a change in the character of the 

 cell-walls of the pith and medullary rays in certain species of 

 Astrarjalus. In the first section of this paper the mode of origin 

 of cherry-gum is minutely detailed. It is a mixture of gum 

 arable and cerasin, the latter allied to bassorin, from which it 

 diflers in its solubility in boiling water. It originates both in 

 the wood and cortical layers, in the latter especially from a 

 transformation of the cells associated with the fibres of liber, 

 Avhich II. Wigand terms Hofoiprosenchym or Hornbast. Nu- 

 merous species belonging to various orders are named in which 



^ this tissue is conspicuous. It is suggested that in some cases 

 Sugar may be foruaed by a similar change jn the cell-waU, as, e.g. 



