CHAPTER XLIII 
INTRODUCTION TO THE CLASS OF FISHES 
The study of fishes is called ich-thy-ol' o-gy. 
So great is the number of species that the mass 
is, at first thought, fairly bewildering. During 
the last twenty years the researches of the men 
who devote their lives to the study of fishes 
(called ich-thy-ol'o-gists) have brought to light 
hundreds of new forms. 
The inhabitants of the waters of North Amer- 
ica, alone, form a great multitude. Of the fishes 
found north of Panama, marine and inland, the 
“Descriptive Catalogue” of Drs. Jordan and 
Evermann, Part IV, completed in 1900, enumer- 
ates the following groups, species and subspecies 
a.s recognized by those authors : 
Orders of Fishes 30 
Families 225 
Genera 1113 
Species 3263 
The four volumes comprising the work men- 
tioned above make a pile nine-and-a-half inches 
high, and contain 3,313 fine-print pages of 
text, and 392 plates. The “Systematic Arrange- 
ment, ” or table of contents, is wholly in Latin, 
and fills 95 closely-printed pages. The work 
has been carefully devised to be of no use what- 
ever to anyone save an ichthyologist. 
When this array confronts the general stu- 
dent, the prospect is rather appalling. From 
the first page to the last, every technical work 
on fishes abounds in descriptive terms that to 
most persons are about as attractive as the 
spines on a porcupine fish. If the general reader 
attempts to master them, he soon finds himself 
involved and discouraged, and the desired gen- 
eral view of our finny tribes is obscured in fog. 
But the whole subject of fish study is merely 
a matter of method. With fishes, as with the 
other vertebrates, the Orders are the master 
keys by which a proper exhibit can be unlocked 
and displayed. At the same time, the Subclass 
divisions are of great importance, and must con- 
stantly be kept in mind. Leaving out the deep- 
sea fishes, which we can well spare for the pres- 
ent, there are twenty well-defined Orders, the 
types of which are almost as easily known and 
375 
remembered as a score of pictures in an art gal- 
lery. The Orders must not be lost sight of, for 
when they are firmly grasped by the understand- 
ing and the memory, the fog begins to rise. 
General Characters. — A typical fish is a 
cold-blooded animal, with a bony skeleton, an 
elongated body which is covered with overlap- 
ping scales, and an outfit of fins for balancing, 
steering and propulsion. It has gills instead 
of lungs, fixed eyes, and a swimming-bladder, 
and is specially fitted for a wholly aquatic life. 
It is provided with teeth, it hears sounds by the 
transmitting power of the bony plates of the 
skull, and usually it lays eggs for the production 
of its young. The body of a typical fish is wedge- 
shaped, narrowest at the tail, thin from side to 
side, and the head tapers to a blunt point. This 
form is specially designed for rapid and easy 
progress through water. 
The Black Bass may fairly be regarded as a 
perfectly typical fish. 
The variations from the perfect type are al- 
most innumerable. For example: 
The Lung-Fish has foot-like fins, and practi- 
cal lungs. 
The Catfish has no scales. 
Some Sharks and a few other fishes bring forth 
their young alive. 
The Rays and Skates are the flattest of all 
vertebrates. 
The Climbing Perch can climb. 
The Flying-Fish can rise from the sea, and fly. 
The Lantern Fish, of the deep sea, carries a 
phosphorescent light upon its head. 
The anatomy of fishes is a special branch of 
knowledge in which the general reader can 
scarcely be concerned, but for the young ich- 
thyologist there are many special works. Books 
for the identification of all the known species 
of fishes in North America are now available 
for those who desire them. At present, how- 
ever, we are concerned only with the twenty 
great groups, or Orders, and the fifty or sixty 
important types which represent them. Of 
these there must be some serious study. 
Up to this date, nearly every systematic writer 
