CHAP. III. FUNCTION OP NUTRITION. 209 



first announced his discovery of a peculiar movement 

 in the juices of plants, which more nearly resembles 

 the circulation of the blood in animals than any thing 

 which had formerly been observed. The existence 

 of such a circulation had been strongly suspected be- 

 fore ; but as the experiments upon which his actual 

 detection of the phenomenon depended were difficult to 

 verify, his account was much disputed until recently 

 when he obtained the prize which the Academy of 

 Sciences at Paris had proposed for the purpose of elicit- 

 ing further investigations on the subject. His memoir 

 has not, hitherto we believe made its appearance ; but 

 the committee appointed to examine its merits have 

 made a favourable report of its contents published 

 in the "Archives de Botanique" for 1833; and from 

 this and a former paper in the "Annales des Sciences," 

 we have gleaned *the following particulars : The 

 liquid, whose movement is described and which M. 

 Schultes terms the " latex," is sometimes transparent 

 and colourless but in many cases opaque, and either 

 milk-white, yellow, red, orange, or brown. The 

 colours depend upon the presence of innumerable mi- 

 nute globules which are constantly agitated as if by 

 a spontaneous motion, and appear to be alternately 

 attracted and repelled by each other. This liquid 

 is considered to be the proper juice of the plant 

 secreted from the crude sap in the intercellular pas- 

 sages and consequently analogous to the blood of ani- 

 mals as was long since suggested by Grew, who 

 further likened the lymphatic or crude sap to their 

 chyle. It is contained in delicate transparent mem- 

 branous tubes, which become cylindrical when iso- 

 lated, but when packed together in bundles assume a 

 polygonal shape. In young shoots it is difficult to de- 

 tect them, on account of their extreme transparency and 

 tenuity ; but they may be extracted with considerable 

 facility from older parts. They have been observed very 

 generally in Monocotyledons and in Dicotyledons, ex- 



