1917] 



Hodgson: Abnormal Water Relations in Citrus Trees 



4.', 



The data in this table indicate that the amount of Mater in the 

 fruit available for use by the leaves was sufficient to maintain the 

 latter alive for approximately 50 hours after the shoot was cut from 

 the tree. It is further evident that when three hours had passed the 

 leaves on the shoot with fruit attached had not yet begun to take water 

 from the fruit to any appreciable extent because the shoot with i'niit 

 detached shows less water loss than the shoot with fruit attached. 

 However, this condition was soon reversed and the leaves began to 



Fig. 1. Showing the difference in per cent of water loss of shoot with 

 orange attached and shoot with orange detached. The water loss curve of the 

 shoot with fruit detached is considered as normal. Ordinates represent differ- 

 ences in per cent of water loss, abscissae, the time elapsed in hours. Water 

 content calculated on basis of fresh weight. 



draw on the water in the fruit while the leaves to which no water was 

 available from the fruit showed indications of wilting. 



That shortly after 50 hours had passed death occurred in the 

 leaves of the shoot with fruit attached is shown by the rapid increase 

 in the amount of water loss. This was undoubtedly due t<; increa 

 permeability of the cytoplasmic cell membranes after death. After 

 50 hours the difference in water content of the two was Is.:'.' in 

 favor of the shoot with fruit attached. However, from this time on 

 until both had reached a constant rate of water loss (after about 200 



