Meyen's Report for 1839 on Physiological Botany. 335 



has at length appeared ; it is written without any regard to 

 the literature which already exists on this subject, so that pro- 

 bably many persons who are not so perfectly acquainted with 

 the literature of vegetable physiology may be deceived by the 

 supposed novelty of the numerous observations here brought 

 forward. 



The work would certainly have been very valuable if it had 

 been printed directly ; but now, at a time when the more deli- 

 cate anatomy has made such great advances, and since the ge- 

 nesis of almost all the elementary organs of plants is tolerably 

 well known, we look in vain in this treatise for all those true 

 improvements of our science ; but, on the other hand, the 

 number of the actually incorrect observations (which may 

 easily be shown) is so very large, that I might fill whole pages 

 with an enumeration of them. M. Schultz has purposely se- 

 parated all the vessels which are figured from the plants by 

 maceration, and of course there must thus arise a great num- 

 ber of mistakes in the figures ; indeed several of them must be 

 considered as ideal sketches, not as representations of nature. 

 The purpose of this treatise is — to prove the existence of a 

 peculiar vascular system in plants in which the circulation 01 

 a peculiar sap, viz. the lacteous sap (Milchsaft) or latex, takes 

 place : M. Schultz denominates this circulation " Cyclosis," 

 but every one who is acquainted with the subject will proba- 

 bly find this new name quite unnecessary. 



On the existence of this circulation of the latex it is well 

 known there has been much discussion, and my readers will 

 remember that the subject has often been mentioned in the 

 former Reports * ; there are however, unfortunately, but few 

 botanists who regarded the observations on this subject with 

 an impartial eye, and I believe that M. Schultz and myself are 

 the only ones who have always endeavoured to prove its ex- 

 istence. In different notices I have circumstantially described 

 how the experiment is to be made with a good microscope, in 

 order to discern the circulation in uninjured plants ; but some 

 elder botanists, who saw clearly that Schultz's view was not 

 correct, would not see this movement ; indeed the opposition to 

 the new theory went so far, that when one wished to show it 

 them they made off, and for several days were not visible. 



M. Schultz has in this treatise done all in his power to 

 prove that the latex moves in a peculiar system of vessels, 

 like the blood of animals in the capillary vessels, and he has 

 given a quantity of figures from different plants to illustrate 

 their mode of anastomosing. Notwithstanding all this, one may 

 read, in the Regensburg Botanical Journal of 1839, p. 277* 



* See Mr. W. Francis's translation, London, 1839, p, 33. 



