346 THE BIOLOQT OF THE PLANT 



water in a dish ; cover the dish with a bell-jar 

 or tumbler in order to prevent evaporation, and 

 study the behavior of the radicle and caulicle. 

 Explain. 

 Make drawings illustrating the facts observed. 



d. Respiration. 



Allow some beans or peas to germinate in a 

 corked bottle with a wide mouth. When they 

 are well started, pour some barium hydrate into 

 a watch-glass, invert the bottle over the glass, 

 and carefully withdraw the cork, holding the 

 mouth of the bottle close to the surface of the 

 liquid. What change in the liquid ? Explain. 



e. Tem/perature of germinating seeds. 



Put some germinating seeds into a beaker under 

 a bell-jar having an open top. Close the top with 

 a stopper having two openings, into each of which 

 is thrust a chemical thermometer. Push one ther- 

 mometer down until its bulb is buried among the 

 seeds. After a few hours take the readings of 

 the thermometers. Explain. 



,/. Some of the chemical contents of germinating seeds. 



Take a number of germinating seeds, e. g., corn, 

 which are just beginning to develop roots and 

 stems, with a knife cut the seeds into small pieces, 

 boil them for a few minutes in a test-tube, and 

 divide the contents of the tube into three parts. 

 Test one part with iodine for starch. Do you find 

 it present? Test the second part with sodium 

 hydrate and copper sulphate for glucose. Is it 

 present ? Test the third portion for the presence 

 of proteids with Millon's reagent. Do you find 



