MOVEMENTS OF PROTOPLASM 



41 



other hand an increase in the proportion of the oxygen does not 

 accelerate the release of energy, or materially modify the per- 

 formance of the organism except so far as it affects the pressure 

 of the other atmospheric elements. 



58. Streaming Movements of Protoplasm in the Absence of 

 Oxygen. Mount a leaf of Philotria, Nitella, or a hair which 

 shows a distinct streaming movement, on a 

 cover-glass 2 cm. in diameter and invert 

 over the opening of an Engelmann gas 

 chamber. Seal the cover to the chamber 

 by a small drop of oil smeared around 

 the edges of the glass and connect the 

 chamber with a hydrogen generator. A 

 number of wash bottles containing a solution 

 of potassium permanganate should be con- 

 nected in the system between the generator 

 and the chamber in order that all impurities 

 should be taken out of the gas. Fasten 

 the attention upon a well-defined strand in 

 a cell and then open the stopcock to allow 

 a current of the gas to flow through the 

 chamber to replace the atmospheric air. 

 After a few minutes, close the stopcock, 

 cutting off the flow of gas, and then quickly 

 clamp the free end of the tubes leading from 

 the gas chamber. This will seal the speci- 

 men in an atmosphere of pure hydrogen. Note the endurance of 

 the movement. Calculate the rate of movement before beginning, 

 by following the movement of a particular granule around the 

 circuit of the cell. Repeat the observation after the hydrogen 

 has been put into the chamber, noticing the change in the rate. 

 After movement has ceased, disconnect the fittings and note the 

 length of time necessary for the resumption of movement. Re- 

 peat the experiment with the same material, and compare data 

 with that obtained from the first test. 



Fig. 21. Cell from a 

 hair of the squash, a, wall. 



b, parietal layer of proto- 

 plasm with chloroplasts. 



c, vacuole, d, small vacu- 

 oles, f, strands of proto- 

 plasm in which moving 

 plastids may be seen. 

 After Belzung. 



