Page:An Introduction to the Study of Fishes.djvu/43

Rh of his anatomical and physiological knowledge should have overlooked the fact that secondary sexual characters are developed in fishes as in any other class of animals, and that fishes undergo great changes during growth; and, consequently, that he described almost all such sexual forms and different stages of growth under distinct specific and even generic names.

The system finally adopted by Cuvier is the following:—

We have to compare this system with that of Linnæus if we wish to measure the gigantic stride Ichthyology has made during the intervening period of seventy years. The various characters employed for classification have been