1896.] Water Current in Cucumber Plants. 457 



passed up through the walls of the vessels, or if this be too 

 strong a statement we are at least safe in saying that not 

 enough passed up the walls to serve even most inadequately, 

 the transpiration purposes of a single leaf, and this, perhaps, is 

 the better forms in which to leave the statement. Neither can 

 it be said, by way of objection that the eosine behaved differ- 

 ently from ordinary water for we have already seen that 1 per 

 cent eosine water passes up unplugged stems readily, even for 

 days and long after the stem is dead. In this case, judging 

 from the state of the atmosphere, the temperature, and the 

 amount of transpiring surface, (approximately 1,500 sq. cm.) 

 at least 25 and probably 50 cubic centimeters would have 

 been taken up by the plant in the first 24 hours but for 

 the gelatine plugs. No explanation is open, therefore, except 

 that the transpiration water passes up through the lumen 

 of the vessels in the stem of the cucumber, and presum- 

 ably in all other stems of similar structure, unless we as- 

 sume that the gelatine passed into the walls of the vessels 

 and destroyed their conductive power, and no one has proved 

 this to be possible or even set forth facts rendering it prob- 

 able. Considering the fact that the walls of the vessels 

 in most plants are solid lignified structures and that the ves- 

 sels are long open tubes, comparable to water pipes and in 

 many plants probably continuous through the whole length 

 of the stem, it would seem strange that this other view, viz. 

 that the water passes upward through the wall itself and not 

 through the lumen of the tube, should have ever gained 

 credence, did we not know how often, even in science, the 

 weight of a great name carries everything before it. 

 {To be Continued.) 



