Growth. 35 



nient to place the seeds on netting fastened over the top of 

 the beaker containing the water and ether (Fig. 19). Line 

 the inside of a bell jar with moist filter paper, then set over the 

 preparation, and seal tight with the cerate. Make a second 

 preparation, but put 5 cm. of ether in the water. Make a third, 

 from which the ether is omitted. Note the appearance of the 

 seeds daily. Compare the period of time elapsing before the 

 germination of the seeds in the three bell jars, and thus deter- 

 mine the influence of ether upon germination. Allow the ex- 

 periment to continue for a week after germination has taken 

 place, replacing the ether solutions with fresh ones of the 

 same strength at the end of the first five days of the test, and 

 allowing the bell jars to become thoroughly ventilated before 

 sealing again to the plates. 



It would be profitable to repeat the experiment, using chlo- 

 roform instead of ether. 



26. Influence of sodium chloride on germination. 

 Pour 400 cubic centimeters of distilled water (or rain water) 

 in each of three vessels of suitable size. Dissolve 3 grams 

 of common salt in one, and 12 grams in another. Soak 100 

 seeds of pea (Pisum) in each of the two jars containing the 

 salt solution, and another 100 in the one containing water 

 only, for twenty-four hours. Transfer the seeds to moist blot- 

 ting paper, each lot being placed under a separate bell jar, or 

 in a separate box of moist sawdust. Note the number of seeds 

 sprouting from each lot. Does sodium chloride exert an influ- 

 ence corresponding to its concentration upon seeds? 



Repeat the test with a one per cent, solution of the salt, 

 exposing the seeds to its action twenty-four, forty-eight, and 

 sixty hours, and note results. 



27. Influence of copper sulphate upon germi- 

 nation. Prepare solutions containing .5, i, 2, 3, 5, and 10 per 

 cent, of copper sulphate in water, and soak lots of 100 seeds of 

 oats in each of these solutions for fifteen minutes. Soak a 



