EXERCISE 88 

 THE GROWTH AND DEVELOPMENT OF A TADPOLE 



Materials. The materials of the preceding exercise. 



Directions. Observe the tadpoles of the preceding experiment during several weeks. Record your 

 observations, including the following points and questions : 



a. Changes in form. 



b. Feeding habits. 



c. Growth. 



d. Appearance of legs. 



e. Disappearance of tail. 



f. Evidences of air-breathing in later stages. 



g. Emergence from water. 



At what stage in the development of the tadpole do the gills disappear ? When does the animal 

 cease to attach itself constantly to some solid object ? Which of the legs appears first ? Are the first 

 legs and the tail used at the same time in swimming ? What becomes of the -tail ? 



Additional problems. What is the food material of frogs and toads when they live on land ? 



Of what economic importance are toads ? 



Is the practice of destroying toads an intelligent practice ? 



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