1917] Hodgson: Abnormal Water Relations in Citrus Trees 47 



The data in table 4 show that at the end of fifteen hours there was 

 a difference in water content between the two fruits of 80.1 ( . There 

 seems to be no way of accounting for this large difference other than 

 that the leaves had actually drawn the major part of it at least, from 

 the attached fruit. 



Water Transport Studies by Means of Dye Stiff Solutions 

 Experiment 5 — Bearing the foregoing findings in mind, it seemed 

 desirable to determine something of the nature of this reversal of 

 normal water flow by means of dye solutions. Accordingly a shod 

 bearing a terminal fruit was cut from the tree and the orange pared 

 away at the apical end to open the tracheal elements and admit the 

 dye. 9 This paring was done under the solution to prevent the en1 ranee 

 of air bubbles. Water soluble eosin was used. The orange was 

 immersed in the liquid for a half hour, after which the shoot was 

 split open. The tracheal tubes throughout all parts of the leaves, 

 stems and fruits were found to be strongly stained. 



Experiment 6 — It seemed desirable to simulate the actual situation 

 on the tree as nearly as possible and the following experiment was 

 designed to accomplish this. A crooked fruiting branch bearing a 

 number of small lateral shoots and leaves, and one terminal orange 

 was cut under water. The cut end was kept under water and the 

 branch so supported that the fruit was immersed in an eosin solution. 

 The apex of the orange was then pared as described above. The 

 branch then rested with its basal end in water and the vascular 

 bundles of the fruit open to eosin at the other end of the branch. 

 (See pi. 12, fig. 2.) If we substitute for the water container the con- 

 ducting system of the tree, and for the watery solution of eosin the 

 developing fruit high in water content, we have very similar condil inns 

 to those existing in the experiment, save for the fact that the fruit is 

 not open to the air and the conducting system bears a certain relation 

 to the rest of the tree. 



The experiment was begun late in the afternoon and the branch 

 left outdoors over night. At 8 o'clock the next morning the leaves 

 were examined and found to be very fresh and turgid. Indeed they 

 were noticeably much fresher in appearance than they had been the 

 evening before. On careful examination absolutely no trace of rosin 



9 It should be stated here that the Washington Navel orange is in reality 

 a double fruit, with a small secondary orange within a large primary fruit. 

 This interior fruit constitutes what is known as the navel and it possesses an 

 independent vascular system of its own which traverses the central pith of 

 the primary fruit before ramifying through the secondary orange. This central 

 pith thus acts as the stem to the small fruit. 



