PHYSIOLOGICAL BOTANY. 249 



promotion." An example of the incomprehensible arro- 

 gance of the author who is bound to a fixed idea. The 

 Academy of Paris certainly awarded him the prize for 

 his Memoir upon the proper vessels, for which no one 

 will censure them, but they declared at the same time, 

 that they do not participate in his views. No academy 

 can test the accuracy of the individual details which are 

 contained in the prize-essays, nor could the Paris academy 

 do so in the present instance. 



There is an analysis of the milky juice of Asclepias 

 Syriaca, by the same author, in the ' Flora/ 1844, p. 374. 



Phytological Studies. By M. le Comte de TRISTAN. 

 4th Mem. Researches upon the Laticiferous Reservoirs 

 and Canals, Ann. des Sc. Nat., 38, t. i, p. 176. This 

 memoir is directly opposed to Schultz's views. Some 

 parts of plants do not contain any laticiferous vessels, 

 hence they cannot serve for nutrition. On the properties 

 of the latex. Varieties in the laticiferous vessels. It is 

 impossible to condense this memoir into the form of an 

 abstract. 



STEM AND ROOT. 



On the Dependence of the Increase of Thickness of 

 Dicotyledonous Trees, on the Physiological Activity of the 

 Leaves. By H. MOPIL. Bot. Zeit., 1844, p. 89. Ac- 

 cording to the theory of Dupetit-Thouars, says the 

 author, the lateral growth of the stem is in connexion 

 with the expansion of the buds, therefore with the for- 

 mation and development of new leaves, and depends upon 

 the circumstance that the buds, in the same manner as a 

 germinating plant, send out radical fibres which descend 

 between the bark and the stem, and form a new layer of 

 wood ; according to another theory, the lateral growth of 

 the stem depends upon the activity of the leaves, because 

 they prepare the nutritive fluid, which is applied to the 

 formation of new woody layers. To decide this point, 



