LEAVES — FUNCTION OR WORK 



103 



Fig. 123. — To ILLUS- 

 TRATE A Product 

 OP Respiration. 



Fig. 124. — KKsi'iRA- 

 tjon of Thick 

 Roots. 



(CO2). 91. In a jar of germinating seeds (Fig. 123) place carefully 

 a small dish of liraewater and cover tightly. Put a similar dish in 



another jar of about the 



same air space. After a few 



hours compare the cloudi- 

 ness or precipitate in the 



two vessels of liraewater. 



92. Or, place a growing 



plant in a deep covered 



jar away from the light, 



and after a few hours in- 

 sert a hghted candle or 



splinter. 93. Or, perform 



a similar experiment with 



fresh roots of beets or 



turnips (Fig. 124) from 



which the leaves are mostly 



removed. In this case, 

 the jar need not be kept dark ; why ? 

 To test transpiration. 94. Cut a succulent 

 shoot of any plant, thrust the end of it through a hole in a cork, 

 and stand it in a small bottle of water. Invert over this a fruit 

 jar, and observe 

 that a mist soon 

 accumulates on 

 the inside of the 

 glass. In time 

 drops of water 

 form. 95. The ex- 

 periment may be 

 varied as shown in 

 Fig. 125. 96. Or, 

 invert the fruit 

 jar over an entire 

 plant, as shown in 

 Fig. 126, taking 

 care to cover the 

 soil with oiled 

 paper or rubber 

 cloth to prevent 

 evaporation from 

 the soil. 97. The 

 test may also be 

 made by placing 

 the pot, properly 

 protected, on bal- Fig. 125. —To illustrate Transpiration. 



