(Edema of the Tomato. 115 



When there is a lack of carbohydrates the amides increase and the 

 protoplasm suffers from farther decomposition.* 



The simultaneous increase of the organic acids tends to overcome 

 the tension of the protoplasm which should hold them in bounds, and 

 they gradually diffuse through it. This may continue until the proto- 

 plasm is killed by the increase and diffusion of these substances. 



This study of the environment of the plants under these conditions 

 of forced culture and the operation of the natural foi'ces and physio- 

 logical processes leads irresistibly to the conclusion that this affection 

 of the tomato plants in a physiological one. 



Confirmed by Experiment. In order to test the effect of the 

 injection of excessive amounts of water into the plant the following 

 experiment was carried out. 



On Monday, December 5th, cuttings, including eight to twelve 

 inches of the top of four tomato plants, were connected with the 

 hydrant as follows: A cork, bored to receive glass tubing sufficient 

 to give four delivery tubes, was inserted in a rubber hose and connected 

 with the hydrant. The cork was then covered with resin and beeswax 

 to prevent leakage. Small rubber tubing was then used to connect the 

 delivery tubes with the tomato cuttings which were supported by being 

 tied to stakes. In turning on the water it was found that the union at 

 the cork was not water tight and it was necessary to leave the experi- 

 ment until the morning of the 6th. 



By this time the cuttings were badly wilted so that they drooped, 

 and the edges of the leaves on one plant were dry. More of the resin 

 and beeswax was brushed over the cork, melted paraffine was run over 

 this and finally it was wrapped with a strip of cloth saturated with 

 melted paraffine which made the union practically water tight. It was 

 also found necessary to. wire the rubber tubing to the end of the cut- 

 tings to prevent them from being thrown out by the force of the water 

 pressure. 



In turning on the water the pressure was so great it was necessary 

 to wrap the larger rubber tube to prevent its bursting. In a few hours, 

 the plants, though they had drooped and wilted so badly, were turgid 

 and upright, only a few leaves of one plant which had dried at the 

 edges not fully opening. On the 7th and 8th, during the middle of the 



* Schulze, Landwirtschaftliche, Jahrbiicher, 1876, Bd. 6, p. 848, 



Bonordin, Bot. Zeitung, 1878, p. 801, cited by Ward, Proceed. Royal Soc, 

 Vol. 47, pp. 343-443. 



Palladin, Ueber Eiweisszersetzung in der Pflanzen, Ber. d. Deustchen Bot. 

 Gesellsch, 1888, p. 205. 



Pfeffer, Piianzenphysiologie, p. 301. 



