PHYSIOLOGICAL BOTANY. 251 



preparation of the nutritive fluid, there is at present no 

 ground for limiting this preparation to the influence of 

 the leaves alone, if the observations definitely indicate 

 another mode. Lastly, against Agardh's view, that trees 

 grow principally in length during the first half of the 

 summer, but principally in thickness during the second : 

 which is not in conformity with observation. 



On the Growth of Internodes, considered Anatomically. 

 By Professor UNGER. Botan. Zeit., 1844, p. 489. 

 This memoir has already been spoken of at p. 230. It was 

 necessarily brought forward there in connexion with the 

 origin of new cells by division, a mode of formation which 

 I should confine to the Algas alone. Here we have to 

 notice the general growth of the parts, of which the author 

 very modestly says, that in one special instance i. e. 

 Campelia Zanonia it takes place not only by the forma- 

 tion of new cells, but also by the increase of those 

 already formed. This law might, in truth, be extended 

 to all the Phanerogamia at least. 



In the ' Coniptes rendus/ 1844, t.i, pp. 899 and 972, 

 we have the fourth notes relative to the protest of M. C. 

 Gaudichaud, of which we have already spoken. 



Continuation of the Anatomical and Physiological 

 Researches upon some Monocotyledons. By M. MIRBEL. 

 (Second Memoir.) Compt. rend., 1844, ii, 689. In 

 this memoir the author gives a very accurate description 

 of the stem of Dracaena Australia (Cordyline Australis), 

 as regards its internal structure, and especially the course 

 of the vascular bundles. He endeavours to prove that 

 the latter arise from the root, and from the inner wall of 

 the stem. He has not only described the stem when 

 perfect, but also when young, and this with great care. 

 I first expressed my views on this subject to the Congress 

 of Italian philosophers at Milan, and they are published 

 in the ' Atti della sesta reunione degli Scienziati Italiani 



