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system OF NATURE. 
of other fishes may be distinguished. It sometimes hap¬ 
pens that moveable articulations which are found in other 
orders are not met with in this, part of the vertebrae of 
certain rays, for instance, being united in a single body : 
some of the articulations of the bones of the face also 
disappear, and the most apparent character of this division 
consists in the absence of the maxillaries and intermaxil- 
laries, or rather in their reduction to mere vestiges con¬ 
cealed under the skin, while their functions are fulfilled 
by bones analogous to the palatines, and even sometimes 
by the vomer. The gelatinous substance which in other 
fishes fills the intervals of the vertebrae, and only commu¬ 
nicates with them by a small aperture, forms, in several of 
the chondropterygians, a long cord which traverses the 
bodies of almost all the vertebrae, without scarcely varying 
in diameter.” — C.R. A. But the great difference appears 
to me to exist in the generation, that of the cartilaginous 
fishes approximating to that of birds and marsupials, a 
complete coition of the sexes taking place, and the young 
being produced either in a perfect form or as an egg, si- 
V 
milar in many respects to that of birds. In true fishes, on 
the contrary, no actual coition takes place, the ova or 
spawn after its extrusion being impregnated by the male 
seminal fluid. As all authors appear to agree on this dis¬ 
tinction it is unnecessary to cite the testimony of either. 
The following definition by Mr. Miller is very charac¬ 
teristic— “ Fishes, the fourth great class in point of rank 
in the animal kingdom, and in extent of territory decidedly 
the first, are divided, as they exist in the present creation, 
into two distinct series, the osseous and the cartilaginous. 
The osseous embraces that vast assemblage which natu¬ 
ralists describe as ‘ fishes properly so called,’ and whose 
