956 
breeding season, alone occupies and guides 
them, is to assuage the internal feeling of 
hunger, to devour almost all that they can. To 
pursue a prey or to escape from a pursuer 
makes the occupation of their life; it is this 
which determines their choice of the different 
situations which they inhabit; it is the prin- 
cipal cause of the variety of their forms and of 
the special instincts or artifices which nature 
has granted to some of the species.” 
“ Vicissitudes of temperature affect them 
little, not only because these are less in the ele- 
ment which they inhabit than in our atmosphere, 
but because their bodies taking the surrounding 
temperature the contrast of external cold and 
internal heat scarcely exists in their case. Thus 
the seasons are not so exclusively the regulators 
of their migration and propagation as amongst 
Quadrupeds or more especially Birds. Many 
Fishes spawn in winter; it is towards autumn 
that herrings come out of the north to shed 
upon our coast their spawn and milt. It is in 
the north that the most astonishing fecundity is 
witnessed, if not in variety of species, at least 
in individuals; and in no other seas do we find 
anything approaching to the countless myriads 
of herrings and cod which attract whole fleets 
to the northern fisheries.” 
* The loves of Fishes are cold as themselves ; 
they only indicate individual need. Scarcely 
is it permitted to a few species that the two 
sexes should pair and enjoy pleasure together ; 
in the rest the males pursue the eggs rather 
than seek the females; they are reduced to 
impregnate eggs the mother of which is un- 
known, and whose produce they will never see. 
The pleasures of maternity are equally un- 
known to most species; a small number only 
carry their eggs with them for a short time; 
with few exceptions Fishes have no nest to build 
and no young to nourish: in a word, even to 
the last details, their economy contrasts diame- 
trically with that of Birds.” 
In no class of the animal kingdom do we 
find such diversity of form as in that of Fishes. 
Some amongst them are perfectly spherical, 
as the Diodons. Others are discoidal, or flat 
and circular, and this shape may be produced 
by two very different conditions, resulting either 
from an excessive narrowing or inordinate ex- 
nsion of the two sides of the body. In the 
rst case it is compressed and much elevated, 
as in Vomer and Orthagoriscus, while in the 
second case it is much depressed, flattened, and 
very broad, as in the Skates. Other species 
are oval, more or less elongated and slightly 
compressed laterally, such as Carp, Trout, &c., 
which is the most ordinary shape. Neverthe- 
less when these become extended longitudi- 
nally (as in the Pikes for example), we are 
insensibly conducted by all intermediate grada- 
tions of form to the cylindrical Eels, or to com- 
pressed and riband-shaped Fishes, such as 
Cepola. Perhaps the most remarkably shaped 
Fishes are those whose bodies are bounded by 
nearly flat surfaces, and which circumscribe 
angular figures, such as triangles, squares, pen- 
tagons, hexagons, &c.,( Ostracion, Syngnathus. ) 
There are even certain genera in which the two 
PISCES. 
sides are not symmetrical, one being flattened 
and the other vaulted, and in these races even 
the bones of the cranium are so disproportioned 
that both eyes are turned to the same side of 
the animal ( Pleuronectide ). 
The following arrangement, being a modifi- 
cation of the classification proposed by Cuvier, 
will facilitate our investigations relative to the 
anatomy of the numerous members of this 
extensive class. ou 
PISCES. . 
Division 1. —~ CHONDROPTERYGII. 
Skeleton cartilaginous, fins supported by 
cartilaginous rays. 
Orpver I.—Branchie fixed. 
1st Family. — PLaciostomata. 
Sygena, Squatina, Pristis, Raia. 
Onper II.—Branchie free. 
1st Family. — Srorionipz. Accipenser, 
Spatularia, Chimera. 
Division I1—OSTEOPTERYGII. 
Skeleton composed of true bone. wi, 
Orpen I—ACANTHOPTERYGII. _ 
The Fishes belonging to this division are at 
once recognised by the stiff spines which con= 
stitute the first fin-rays of the dorsal fin, orwhich 
support the anterior fin of the back in ¢ 
there are two dorsals. In some cases the an- 
terior dorsal fin is only represented by detached 
spines. The first rays of the anal fin are like- 
wise spinous as well as the first ray of the ven= 
tral fin. This order, which comprises by far 
the greater nuinber of osseous Fishes, is divi- 
sible into the following families. 
1st Family.— Percivz. Perca, Lab 
Lates, Centropomus, Grammistes, Aspro, Apo- 
gon, Cheilodipterus, Pomatomus, Ambassis 
Lucio-Perca, Serranus, Plectropoma, Diac pe, 
Mesoprion, Acerina, Rypticus, Polyp 
Centropristis, Gristes, Cirrhites, Chirone: 
Pomotis, Centrarchus, Priacanthus, Dule 
Therapon, Pelutes, Helotes, Trichodon, Sill 
Holocentrum, Myripristis, Berys, Trachichti 
Trachinus, Percis, Pinguipes, Percophis, Ura 
oscopus, Polynemus, Sphyrena, Para 
ullus. a 
2nd Family.—SciERocEntpz (hard cheek 
Trigla, Prionotes, Peristedion, Dactylopter 
Cephalacanthes, Cottus, Hemitripterus, He 
lepidotus, Platycephalus, Scorpena, Pt 
Blepsias, Apistes, Agriopes, Pelors, ce 
Monocentris, Gasterosteus, é * 
Sciena, Eq 
Squalus, 
3d Family. — Scianipz. 
Hemulon, Pristipoma, Diagramma, Lobo 
Cheilodactyles, Scolopsides, Micropterus, 2 
ee Premnas, Pomacentres, Dascyli 
Glyphisodon, Heliases. a 
4th Family.—Sparivz. argus, Chry 
phris, Pagrus, Pagellus, Dentez, ’ 
Boops, Oblada. a 
5th Family—Manyipz. Mena, Smar 
Casio, Gerrus. ss 
6th Family. — SguaMMIPENNES. 
