CLASS AMPHIBIA. 305 



313. Topics for Themes in Zoology and English. 



1 . Give an account of the breeding habits of the follow- 

 ing forms : The obstetrical toad of Europe ; the Surinam 

 toad of South America; the pouched tree-frogs of South 

 America. 



2 . Give the history of the Mexican axolotl. 



3. The color changes of the tree toad, Hyla versicolor. 

 How are they produced? 



4. The amphibians in geological history. 



5. The noises made by frogs. How are they made 

 and what is their value? 



6. How do frogs spend the winter? How do toads? 



7. Make definite studies of amphibians and their 

 behavior during the spring months. 



