APPENDIX 



185 



C. Absorption of food (Exercise 10, Frog) 



(A demonstration to be made by the teacher.) 

 The apparatus should be set up and the materials put in about 

 two days before the final demonstration to the students is 

 to be given (c/. Fig. 77). 



m 



Fig. 77. — Diagram for comparison of the tubes separated by parchment and 

 a cross section of the digestive tract. 



Equipment J or setting up apparatus: 



2 tall glass cylinders (tube B). 



2 smaller glass tubes (tube A). 



Parchment paper and thread. 



Starch paste. 



Sugar: Dextrose (grape sugar, glucose) should be used. 



Distilled water. 

 Equipment for demonstrating to students: 



Apparatus as set up. 



Several test-tubes. 



Test-tube holder. 



Test-tube rack. 



Gas burner and matches. 



Pipettes with long tubes to take material from jars. 



Benedict's or Fehling's solution. 



Starch solution. 

 Tests: 



Starch, blue color with iodine. 



Sugar, Benedict's or Fehling's test. 



