GEMMEOUS DRAGONET. 
277 
of a. darker brown, which on the lower part of the fin 
becomes almost black. The lowest ray is entirely white, 
and the next to the lowest white at the tip. 
3. Young male. When very young, the male is 
extremely like the female; and until Fries’s time the 
two sexes of this species in their juvenile stage were 
confused by most ichthyologists who had not examined 
the internal sexual organs. The same colour, the same 
short head, the same relative size of the parts of the 
body meet us in the young males as in the females, 
'fhe only external point by which we can always re- 
cognise the young male, is the somewhat greater height 
of the first dorsal fin, which is always somewhat higher 
at least than the second dorsal, and always without the 
black colour between the rays. But as it grows, the 
young male has less and less of the appearance of the 
female, and gradually adopts the shape and dress which 
belong to the full-grown male. This transition may 
be illustrated most clearly by a comparison between 
young males of different sizes. Let us choose four 
specimens, the first 163 mm. in length, the second 179, 
the third 197 and the fourth 222. In the first the 
length of the head to the occiput is not quite 1 / 5 of 
the length of the body, in the second exactly 7r>- In 
both the relative length of the snout is the same as in 
the full-grown female. In the third specimen the length 
of the head is somewhat more than 1 / 5 of that of the 
body, and the distance between the tip of the upper 
jaw and the eye is equal to that between the anterior 
margin of the eye and the gill-opening, but less than 
that between the posterior margin of the eye and the 
margin of the operculum. In the fourth specimen the 
length of the head is still greater in proportion to that 
of the body, and the length of the snout is very nearly 
as great as in the full-grown male. In the first speci- 
men the first ray of the first dorsal fin measures less 
than 7d °f the length of the body, but in the fourth 
specimen more than 1 / s thereof. In the first specimen 
the tip of this ray, when depressed, extends to the tip 
of the first ray of the second dorsal fin, in the second 
specimen to the tip of the fourth ray of the latter fin, 
and in the fourth specimen to the tip of the sixth ray 
thereof. In the first three specimens the tAvo dorsal 
fins are still separated at the base, as in the full-groAvn 
female, in the fourth, on the other hand, they are al- 
most united. In none of these specimens does the last 
ray either of the second dorsal fin or of the anal, Avhen 
the fin is depressed, yet extend to the base of the 
caudal fin, but the distance gradually decreases from 
the first specimen to the fourth. 
The coloration of all four is most like that of the 
female, but here and there in the first two specimens, 
and still more frequently in the fourth, we find some- 
thing of the dress of the older males. 
We have never found a single young male during 
the spaAvning-season Avith the sexual organs fully de- 
veloped; and Ave therefore conclude that all of those 
Avhich have the colouring and the external characters 
described above, are not yet capable of propagating 
their species. They probably do not possess this poAver 
until the first dorsal fin (taken as an example of the 
general development) has attained the length it pos- 
sesses in the old males. IloAvever, as Ave used the 
length of the body to express a comparison between 
the specimens, it may not be superfluous to remark 
that the length of the fish cannot ahvays be regarded 
as a trustworthy measure of its age. Among numerous 
individual exceptions Ave have found a male fully de- 
veloped, but only 200 mm. in length. 
On examination of the intestines as they lie in 
the abdominal cavity Ave find an unmistakable resem- 
blance between the Gemmeous Dragonet and the Bull- 
heads. The intestinal canal is fairly long. The sto- 
mach, Avhich is Avithout any trace of pyloric appendages, 
appears only as an expansion of the intestine. The 
intestine proper forms several bends, and has extremely 
thin Avails. The liver, Avhich is of a nankeen-yelloAV, 
consists of one single piece, Avithout true lobes. It lies 
principally to the right, and partly envelops the first 
bend of the intestine. The gall-bladder is small and 
oblong, and lies in an incision in the liver. The air- 
bladder is Avanting. The kidneys are triangular, and lie 
Avith the broad end in front, posteriorly tapering to a 
point. The urinary bladder is large, clear, thin-Avalled 
and obovate. The peritoneum is Avhite and shiny. The 
ovaries are united behind, but distinct in front. The 
testicles are oblong and distinct, and in the young male 
are externally much the same as in certain birds. They 
are situated someAvhat behind the middle of the ab- 
dominal cavity. 
Of the peculiarities of the skeleton Ave shall re- 
mark only the absence of the subcranial tube (for the 
optic muscles); the partition wall between the orbits, 
on the other hand, is ossified to a great extent, at 
least in front (os orbitosphenoideum ), though thin. The 
operculum and preoperculum are considerably reduced, 
