24 SOME RECENT RESEARCHES IN PLANT PHYSIOLOGY 



The following typical experiments, quoted from a large 

 number recorded by Parkin, formed the data from which 

 the previously quoted conclusions were drawn : 



(a) April 8, Carlisle: Maximum shade temperature, 

 58 F. ; minimum temperature previous night, 32 F. 



TABLE XII. 



8.15 a.m. 4.15 p.m. 



Sucrose 8-88 12-92 



Hexose .. 9-40 10-74 



Total sugar . . . . 18-28 23-66 



The total increase is nearly 5J grammes, very largely 

 due to sucrose. 



(6) April 5 and 6, Carlisle : Maximum shade temperature, 

 58 F.; minimum during the night, 39 F.; maximum 

 shade temperature on 6th, 52 F. 



TABLE XIII. 



4.30 p.m. Noon Next Day. 



Sucrose 14-65 7-80 



Hexose 13-66 13-29 



Total sugar .. .. 28-31 21-09 



The plants were covered, when the first lot of leaves was 

 gathered from them, and kept in darkness till the time of 

 taking the second batch the following noon; thus no 

 assimilation could take place. 



Nearly 7 grammes of sugar have disappeared, due solely 

 to reduction in the sucrose. The hexose has remained 

 almost constant. The conditions were favourable for the 

 translocation of sugar. 



The following experiment gives an indication of the 

 amount of sugar disappearing from the leaf otherwise than 

 by translocation. The plants were in a darkened frame 

 overnight. 



(c) March 7 and 8, Cambridge : 



