INTRODUCTORY 7 



or taxonomist, classifying the fishes, and arranging them in 

 larger or smaller groups according to their differences and 

 resemblances; the statistician, dealing with minute variations 

 and huge numbers of individuals; the physiologist, studying 

 living activities and the function of organs and tissues ; and the 

 "field" naturalist, observing the relation of living fishes to 

 their environment; each of these is continually adding his 

 quota to the sum total of our knowledge of the science of fishes. 

 Moreover, the story of fish life does not begin and end with the 

 fishes living at the present time, but had its commencement 

 ages and ages ago, long before man made his appearance on 

 this planet, and when there were no reptiles or amphibians, 

 no birds, and no mammals. For facts concerning the past 

 history of fishes we are indebted to the geologist, who studies 

 the formation of the rocks wherein the records lie buried, and 

 to the palaeontologist, who spends his time searching the dried- 

 up basins of ancient seas and lakes, and describing the fossilised 

 remains which may be found there. As will be shown later on, 

 the story of the rocks — the geological record, as it is called — 

 is necessarily fragmentary and very imperfect, but has already 

 provided a mass of evidence which has confirmed or modified 

 the conclusions drawn from the study of anatomy, embryology, 

 etc. Nor is this all. The body of a fish, as well as its inanimate 

 environment, is continually subject to physical and chemical 

 laws, so that, in order to arrive at a full understanding of fish 

 life, it is necessary to go beyond the realms of pure biology and 

 draw upon the researches of the chemist, physicist, meteorol- 

 ogist, and even the mathematician. 



The history of ichthyology, like that of zoology itself, may 

 be said to have begun with Aristotle, who recorded a vast 

 array of facts concerning the fishes of Greece. His information 

 relative to their structure, habits, migrations, spawning seasons, 

 etc., is, so far as it has been tested, extraordinarily accurate, 

 but his ideas of species were exceedingly vague, being simply 

 those of the local fishermen from whom he obtained the names 

 of his specimens. As Dr. Giinther has observed: "It is less 

 surprising that Aristotle should have found so many truths as 

 that none of his followers should have added to them." Pliny, 

 Aelianus, Athenaeus, and others certainly recorded some original 

 observations, but the majority of scholars from the time of 

 Aristotle until some eighteen centuries later were content to 

 copy from his works, merely adding a number of fabulous 

 stories and foolish myths. In the middle of the sixteenth 



