10 SEEDS 
the level of the water. What is the relation between the 
increase in the volume of the peas and the decrease in the 
volume of water? What causes the peas to become 
larger? 
Exp. 8: Mix the 25 peas used in the preceding ex- 
periment with small pieces of wet blotting paper and 
put them into a 50 c. c. wide mouthed bottle. Close the 
bottle tight and set it aside until the peas have radicles 
about 6 mm. long. Carefully open the bottle and insert 
a burning splinter, also insert a burning splinter into a 
similar bottle without peas. Results; conclusions? 
After the splinter has been inserted close the bottle air 
tight and compare the growth of the peas in this bottle 
with that of those in the open bottle used in exp. 5.’ 
Exp. 9, Class: Obtain four 50 c. c. wide mouthed 
bottles, an 8 to 15 liter bottle, a small bell-jar with an 
opening at the top, and rubber stoppers with two holes 
each, to fit all the bottles and the jar. Run a glass tube 
thru each hole in the stoppers; one should extend to the 
bottom of each bottle, the other only a short distance 
beyond the lower surface of the stoppers. Set the bell- 
jar into an open dish containing water several centimeters 
de‘ p, and connect the glass tubes with pieces of rubber 
tuLing so as to make an air tight series consisting of 
two of the 50 c. c. wide mouthed bottles, then the bell- 
jar, then the two remaining small bottles, and finally 
the large bottle. Fill the large bottle entirely with 
water and the four small bottles about one-third with 
clear lime water, Ca(OH)2. Procure a wide mouthed 
bottle nearly 10 cm. high, containing vigorously grow- 
ing pea seedlings with radicles about one centimeter long, 
