SOME FACTS ABOUT FISHES. 
47 
ther as haying the head more nearly in proportion to the body, 
although the eye is still large and the forehead steep, but less so 
than in that just noticed ; the beak is still formed of the two 
jaws, fully armed with teeth, hut the upper jaw slightly exceeds 
the lower one ; the dorsal fin has become much more elevated, 
and, with the anal fin, is already furnished with rays ; and the 
ventrals have become developed into long styliform appendages. 
A third specimen, about 2J inches (60 mi Him.) long, has already 
acquired nearly the form and proportions of the adult; the 
upper jaw is considerably produced beyond the apex of the 
lower one, and both jaws have lost their armature of teeth ; the 
parietal spine has vanished, and the praeopercular one is com- 
paratively small, while the fins have attained pretty nearly 
the proportions which they have in the full-grown fish. The 
little animal is, in fact, an unmistakable Swordfish, and only re- 
quires a little further elongation of the beak formed by the 
upper jaw to be a close likeness of its parents. 
The Garfish, forming the family Scomberesocidse, and one 
species of which, the common Garfish or Greenbone (Belone 
vulgaris ), may not unfrequently be seen in the fishmongers’ 
shops, present phenomena of development to some extent analo- 
gous to those observed in the Swordfishes. The adult fish has both 
jawsmost curiously prolonged into slender-pointed beaks, of which, 
i however, the lower one is the longest ; but in the very young 
fish, although the form and general character are very similar 
i to those of the adult, there is not a trace of this singular pro- 
longation. It soon begins to make its appearance, however, and 
the length of the jaws gradually increases until the mature form 
is attained. In the course of this development, the dispropor- 
tion between the two jaws is for a time very considerable, espe- 
cially in the common Garfish, which at one period seems to 
reverse the characters of the Swordfish, having the lower jaw 
produced into a long slender beak, while the upper one is not 
remarkably elongated. 
The development of some fishes of the genus Holocentrum, a 
somewhat perch-like group inhabiting tropical seas, presents a 
contrast to that of the Swordfishes in another way, — the young 
fishes are furnished not only with opercular and cephalic spines, 
which afterwards disappear more or less, but also with a pro- 
jecting beak from the upper jaw, which is often serrated, and 
sometimes forked at the apex, but which always vanishes as the 
fish approaches maturity. These young forms of Holocentrum , 
and of the allied genus Myripristis , have been described as form- 
ing distinct genera under the very appropriate names of 
Rhynchichthys , Rhinoberyx, and Rhamphoberyx. 
It would carry us too far to attempt to indicate anything 
like the whole of the phenomena presented by fishes in their 
