14 NATURE TEACHING 



in A the seeds do not germinate at all ; they have no 

 water at all, and very little air. In B the seeds have 

 water but again very little air; they will probably ger- 

 minate and grow for a short time, and then, having 

 exhausted the air, die. The seeds in C have water, and, 

 the bottle being open, air also. (The blotting-paper in 

 C should be kept moist by the addition of water from 

 time to time.) They should germinate and grow well. 

 Those in D, although provided with water, have no air. 

 They should grow but slightly, if at all. The experi- 

 ment has so far shown the necessity of water and air. 

 Keep careful notes of this experiment, recording the 

 number of seeds which germinate at all in each bottle 

 and the heights the seedlings attain. 



In order to show the influence of temperature, take 

 two pots filled with soil, properly prepared for the recep- 

 tion of seeds (see p. 1 5). In each pot place two or three 

 seeds of several different kinds, for example, beans, peas, 

 barley, radish, etc. Label the pots, and place one out of 

 doors and keep the other indoors in a warm place, such 

 as in the kitchen, or warm school-room. Keep the soil 

 in both pots suitably moist. Note in your note-book the 

 date when the seeds were sown and the dates on which 

 the various seedlings first appear above the surface of 

 the soil. Measure the heights of the young plants at 

 regular intervals. Compare the rate of germination and 

 early growth of the plants in the pot kept warm and in 

 that exposed to cold, and draw conclusions as to the 

 effect of temperature upon plant life. 



Note. This experiment should be made between 

 the months of October and March. 



