W. A. Davis, A. J. Daish and G. C. Sawyer 295 



B. 



The Sugars of Mid-ribs and Stalks (Petioles). 

 The Translocation of the Sugars. 



Series I. 



August 26th-27th, 1913. 



In this series, the leaf-stalks (petioles) were divided into top and 

 bottom halves, and the two sets were treated separately ; in this way 

 it was hoped that any change in the saccharose and hexoses during their 

 passage to the root might be detected. Actually it was found that 

 very considerable diflerences exist in the composition of the sap in the 

 two halves, as shown by the data in Table V. 



Table V. Series I. August 26th-27th, 1913. 

 Top and Bottom Halves of Mangold Leaf-stalks. 



In Series II the mid-ribs of the leaves were cut out and dealt with 

 separately. The stalks in this series were treated as a whole, and not 

 subdivided into top and bottom halves. 



A careful comparison of the data in Tables V, VI, VII and VIII, 

 and Figs. 7 to 10 gives important information as to the translocation 

 of the sugars from the leaf to the root. The following are the principal 

 points disclosed : 



1. The proportion of sugars and of matter soluble in alcohol is 

 always far greater in the stalks and mid-ribs than in the leaves at the 

 same picking: thus, for example, in Series I, 12 noon. 



