Chinook salmon (Oncorhynchus) 



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Leopard frog {Rana palusihs) 



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Spotted salamander 

 {Ambystoma maculatum) 



METAMORPHOSIS IN VERTEBRATES 



Among the vertebrates only amphibians seem to have the distinct stages making up 

 a "metamorphosis". Among birds and mammals the transformations during the in- 

 dividual's development are much more complex, but they take place within the egg 

 or within the body of the mother, so that the individual has already attained the 

 general form distinctive of the species when he first appears as "free-living" 



