48 



NATURAL HISTORY. 



[Lesson VIII. 



jelly, found floating in these places ; some 

 that look like bunches of grapes, the others 

 like strings of heads. The first is the 

 spawn of toads, the other of frogs ; and these 

 necklaces of heads (as it were) gradually 

 get heads and tails, and grow on until they 

 have legs, and lose the long tail they each 

 had. The gills disappear, and they then 

 breathe hy means of lungs ; and from 

 vegetable they gradually ascend to insect 

 food, which they swallow whole, slugs and 

 beetles disappearing in large numbers. 



GENERAL QUESTIONS ON LESSON VII. 



1. What is the name of the third class 

 of Vertebrate animals? 



2. What peculiarity marks or dis- 

 tinguishes the cl.i 



3. Are they warm or cold-blooded 

 animals ? 



4. Why are Reptiles separated from 

 other Vertebrate aninuils ? 



5. Can they suspend respiration ? 



6. Why are Reptiles covered with scales? 



7. How many orders of Reptiles are 

 there according to Cuvier, and how many 

 according to other naturalists ? 



8. Where are Reptiles (.-enerally found ? 



9. State some peculiarities found or 

 observed in the fourth order of Reptiles. 



10. When and where do the transforma- 

 tions of frogs, toads, and others of this 

 order take place ? 



LESSON VIII. 



WE did not adcfpt the classification of some zoologists in our last lesson, and divide 

 the Reptiles into two parts, so as to make a fourth class, called Amphibious animals, 

 because the great Cuvier did not do so, and we wish to adhere to his system. GRANDFATHER 

 WHITEHEAD is a zealous disciple of Cuvier, and does not desire to depart from his plan. 

 There may be good reasons for separating the Reptiles, into those strictly inhabiting the 

 land, and those that are amphibious ; but although the AMPHIBIA are intermediate 

 between Fishes and Reptiles, they are destitute of scales or hard plates ; a gooo 1 reason, 

 some will say, that they should be divided from the Reptiles; hut GRANDFATHER 

 WHITEHEAD thinks differently, and therefore adopted the system of Cuvier. Perhaps, 

 some day, he will give his reasons, in his " Lectures to Little-Folk." 



We have now to consider the last class of the Vertebrate animals Fishes. They have 

 a double circulation, respire through the medium of water, and. consequently, can live 



beneath its surface. Their structure is pe- 

 culiar, because they have little or no weight to 

 hear. Their bodies are formed for the purpose 

 of easy propulsion, being of nearly the same 

 specific gravity as the fluid they inhabit, and 

 furnisi'ed with fins, Ly means of which, and 

 the lateral movements of the tail and body, they 

 arc enabled to move without much effort. It is 

 the texture of the fins that is so important in 

 their classification, and therefore the proper 

 arrangement of Fishes is a very difficult matter; 

 but, nevertheless, we are enabled to divide them into two great divisions Bony and 

 Cartilaginous Fishes. The number of the fins varies in different groups, and assists in the 

 arrangement of the orders and species. 



* Fig. 12. Whitebait, a, dorsal fin; b, candai iiu, or tail; c, anal fin; d, ventral fin; e, pectoral 

 fin of one side. 



