THE FLOWEEING PLANT — SEEDS 343 



sponge immersed in water, but held tightly- 

 squeezed in the hand. 



Provide a glass tube about four inches long and 

 two inches in diameter and open at each end, 

 two pieces of thin parchment well soaked in 

 water and sufficiently large to tie over the ends 

 of the tube, about two table-spoonfuls of syrup 

 (or, better, the same amount of grape-sugar or 

 glucose), a piece of strong twine, and a dish 



. holding about a pint of distilled water. Over 

 one end of the tube tie a piece of the moistened 

 parchment so tightly that it cannot slip off, but 

 leave that part of it which covers the calibre of 

 the tube somewhat loosely wrinkled or plaited. 

 Pour in the syrup, diluted with sufficient water 

 to fill the tube, or put in the dry grape-sugar, 

 and fill the tube with water. Tie over the open 

 end the second piece of moistened parchment, 

 arranged like the first. Turn the tube first on 

 one end, then on the other, to see that none of 

 the syrupy fluid within can come out, then place 

 it in the dish of distilled water. Examine the 

 tube from time to time to see whether or not 

 the parchment is become tense and outwardly 

 convex. What makes the parchment bulge? 

 Are the conditions of the experiment at all 

 similar to those of a plant-cell — e. g., one of the 

 cells of Spirogyra — immersed in water ? Com- 

 pare the end walls of the tube with the ends of 

 a filament of Spirogyra. If a plant-cell whose 

 walls were more or less flaccid, and whose con- 

 tents were a fluid — i. e., cell-sap — denser than 

 water, be placed in the latter, would the cell 

 absorb some of it ? Would the walls become 



