CHAPTEK I. 



HISTORY AND LITERATURE. 



Aristotle. TiiE commencement of tlie history of Ichthyology coincides 

 with that of Zoology generally. Aristotle (384-322 B.C.) 

 had a perfect knowledge of the general structure of fishes, 

 which he clearly discriminates from the Aquatic animals with 

 lungs and mammas, i.e. Cetaceans, and from the various groups 

 of Aquatic Invertebrates. He says that " the special charac- 

 teristics of the true fishes consist in the branchiae and fins, 

 the majority having four fins, but those of an elongate form, 

 as the eels, having two only. Some, as the Iliircena, lack the 

 fins altogether. The Eays swim with their whole body, which 

 is spread out. The branchise are sometimes furnished with 

 an opercle, sometimes without one, as is the case in the carti- 

 laginous fishes. . . . ISTo fish has hairs. or feathers; most are 

 covered with scales, but some have a rough or smooth skin. 

 The tongue is hard, often toothed ; and sometimes so much 

 - adherent that it seems to be wanting. The eyes have no lids; 

 nor are any ears or nostrils visible, for what takes the place 

 of nostrils is a blind cavity. Nevertheless they have the 

 senses of tasting, smelling, and hearing. ' All have blood. All 

 scaly fishes are oviparous, but the cartilaginous fishes (with 

 tlie exception of the Sea-devil, which Aristotle places along 

 with them) are viviparous. All have a heart, Kver, and gall- 

 bladder ; but kidneys and urinary bladder are absent. They 

 vary much in the structure of their intestines : for whilst the 

 mullet has a fleshy stomach like a bird, others have no 



