CHAPTER II 



TIM. CHAK.UTKKlSTirs OF VALUABLE MARINE FISHES AND 

 THF REGIONS IN WHICH THEY LIVE 



Tin: word fish is often used to include nearly every creature 

 that lives in the sea. We talk of star-fishes and of shell-fish, as 

 \vcll as of fishes in the stricter sense. The oyster and the 

 lobster are both called shell-fish, notwithstanding the great 

 difference between them in the matter of legs and claws. The 

 passive, transparent objects which we call jelly-fishes have no 

 resemblance to either a star-fish, oyster, lobster, or fish. Then 

 again the whale and the porpoise are often called fishes, and 

 supposed by many people to be quite correctly so called. But 

 in order to learn something about the history and origin of these 

 creatures and how they live, we must take the trouble to study 

 the differences between them. We must find out how many 

 principal kinds of animals there are in the sea, bringing together 

 those that are alike and separating those that are unlike. This 

 i-, the first step towards the recognition and identification of the 

 various kinds in all the stages and periods of their lives. 

 What is found to be true of one kind of animal or one kind of 

 fish may not be true, and in fact very often is not true, of another 

 kind. A correct knowledge of certain facts about the history of 

 some particular fish may be and often has been seriously mis- 

 understood, when the various kinds have not been properly 

 distinguished. 



Now in the first place there is one grand difference among 

 animals in the construction of their bodies, namely, that some 

 possess a back-bone, and others do not. We ourselves have a 

 back-bone, and likewise beasts, birds, reptiles, frogs, and fishes. 



