76 



CULTUEE OF THE SUGAR BEET. 



If a root be cut in the direction of its length and through its center, it shows the 

 section rej>resented in Fig. 7. bbb are the parts containing the sugar. They are dis- 

 tinguished by their more decided white appearance ; all the tissue which separates 

 them is grayish, and contains little or no sugar. This is proven by chemical tests, by 

 cupric liquor among others, or even simply by the taste. 



Champion and Pellet state * that — 



If very thin slices of pink beets be used, after a few minutes' exposure to the air, 

 the zones pointed out by Payen may each be subdivided into two different zones, sep- 

 arated from each other by a series of black points (tubes) distributed in the form«of 

 circles, and seeming to correspond with the leaves. 



The structure would then be as follows : 1, opaque zone ; 2, trans- 

 parent zone ; 3, opaque zone ; 4, zones of vascular tissue. 



The formation of these zones seems to be in some way allied to the 

 production of leaves, as well as the increased proportion of sugar con- 

 tained in them, for Bretschneider noticed a relation between the number 

 of leaves and of the concentric layers, and Gaudichaud found that u the 

 leaves of beets correspond directly with the different zones of vessels in 

 the roots in such a way that the appearance of new leaves should always 

 give rise to new zones of vessels"; while in connection with the above 

 facts Champion and Pellet give the following figures, showing the rela- 

 tion between the percentage of sugar in the juice, the number of leaves 

 on the plant, and the number of zones in the root : 



Payen's notions found support in the results of examinations of the 

 parts made by Joulie, Violette, and others. Notwithstanding the earlier 

 statements of Violette, he has published results of analyses showing that 

 the percentage of sugar in the several parts varies inversely with the 

 distance of the part from the longitudinal axis, and that the higher 

 percentage is found in the opaque zones. Thus the same beet gave 

 the following figures : 



Translucid zones . 



Opaque zones. 



Per cent. 



( 14.5 



1 13.4 



( 10.0 



C 15.7 



< 15.5 



/ 11.2 



In his earlier work, Violette found little difference in the quantity of 

 sugar present in the two kinds of tissue, but the notions then obtained 



* La Bettrave a Sucre, p. 58. 



