334 DATE SUGAR INDUSTRY IN BENGAL. 



During our experiments careful observation was kept of the 

 daily maximum and minimum temperatures. The records of 

 temperature are unfortunately not complete owing to continual 

 absences on tour from Kotechandpur. 



The charts shew that the yields are greatest during the coldest 

 months of the year. Sudden changes in temperature seem to have 

 very marked effects on the yield of juice. Thus on January 7th 

 the temperature was very low. The yield of juice immediately 

 after that date rose rapidly, though it is to be noticed that the 

 effect of a cold night is not always seen that same night in an 

 increased yield of juice. This increase comes the following 

 night as a rule. 



Kise of temperature results in immediately reducing the 

 quantity of juice. This is well seen in the curves. From January 

 10th to 15th the night temperature rose rapidly. A sudden fall in 

 yield is shewn in all the curves. From January 15th to 17th the 

 night temperatures rapidly decreased. Most of the yield curves shew 

 a corresponding rise in accordance with this. Towards the end of 

 the season the yields of juice are too small to shew any marked 

 variation corresponding to changes in temperature. 



The writer suggests that during cold weather little growth 

 of new leaves or flowers takes place in the tree and hence the colder 

 the weather the more sap there is available to flow to the cut surface. 

 Directly the temperature rises, growth goes on more rapidly and the 

 supply of sap is diverted from the cut surface to the growing points. 



With regard to the amount of sugar in the juice the curves give 

 us interesting information. In all of them is to be seen a distinct con- 

 nection between the yield of juice and its sugar content. As a general 

 rule the smallest yields are the richest in sugar. Fischer 1 reports 

 that when bleeding is active, the sap becomes gradually poorer and 

 poorer in sugar. 



1 Pfeiffer's Physiology of Plants, Ewart, Vol. 1. 



Since writing this the author finds that a similar phenomenon has been noticed in the 

 case ot the maple tree in America (see Studies of Maple sap by Morse, Bull. No. 32, September 

 1895, New Hampshire College, Agric. Expt. Statn., page 4). 



