(JKMMEOUS I)RA(;0N1',T. 



277 



of ii (hirkcr hrowii, \\hi<'li on tlic lower p.'irt of tlic (in 

 becomes almost lilnck. The lowest my is cntircK white, 

 iliul the next to the lowest wllite at the tip. 



3. loitiifi ))Hil('. \\ lien \'ery vounii', the iiinle is 

 exti'enieh' like the f'eni.ile; .ind until l''i;iKs's time the 

 two sexes of this speeies in their juNcnik; sta;f(; were 

 confused hy most iehtluoloii'ists who hiid not exiimined 

 the intei'iiMJ sexuiil oi'g;ins. The same coloin-, the Mime 

 short head, the same relative size of the |);ii-ts of the 

 body meet us in tiie xduiii:' niMJes as in the fem;des. 

 The only external point 1>\' which we can ;dwa\s re- 

 cognise the youniz male, is the somewhat greatei- lieiiiht 

 of the first (h)rs;il tin, which is alwa^'s somewhat hiiiher 

 at least than the second doi'sal, and alwa\s without the 

 black colour between the rays. But as it grows, tiie 

 young male h:is less and less of the appearance of the 

 female, and gradually a(lo|>ts the shape and dress which 

 belong to the full-grown male. This transition may 

 be illustrated most clearh' 1)\' a coni|)arison between 

 young males of diftereiit sizes. Let us choose four 

 specimens, the tirst Kio nun. in length, the second 179, 

 the third 197 and the fourth L>2-2. In the first the 

 length of the head to the occiput is not quite Vo <'f 

 the length of the body, in the second exactly ' -. 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 ' -, of that of the 

 body, and the distance between the tip of the upper 

 jaw and the eve is equal to that between the anterior 

 margin of the eye and the gill-opening, but less than 

 that l)etween the posterior margin of the eye and the 

 margin of the operculum. In the fourtli specimen the 

 length of the iiead is still greater in projjortion 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 v., of the length of the body, but in the fourth 

 specimen more than ' 3 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 lattci- fin, 

 and in the fourth specimen to the tip of the sixth ray 

 thereof. In the first three specimens the two dorsal 

 fins are still separated at the base, as in the full-grown 

 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 doi'sal fin or of the anal, when 

 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 aii<l there in the first two specimens, 

 and still more frefjuentl\- in the fourth, we find some- 

 tiling of the dress of the older males. 



We have never found a single young male during 

 the spa\\'ning-seasoii with the sexual organs fully de- 

 veloped; and we therefore conclude that all of those 

 which have the colouring and the external characters 

 described above, ai'e not yet ca|)al)le of propagating 

 their species. The\ probabK do not ])08sess this power 

 until the first dorsal fin (taken as an example of the 

 genei-al develo])ment) has attained the length it pos- 

 sesses in the old males. However, as we used the 

 length (jf the bo<lv to express a comparison between 

 the specimens, it may not be superfluous to remark 

 that the length of the fish cannot always be regarded 

 as a trustworthy measure of its age. Among numerous 

 individual exceptions we have found a male fully de- 

 veloped, l)ut only 200 mm. in length. 



On examination of the intestines as thev lie in 

 the abdominal cavity we find an unmistakable resem- 

 blance between the Gemmeous Dragonet and the Bull- 

 heads. The intestinal canal is fairly long. The sto- 

 mach, which is without any trace of p)-loric appenflages, 

 appears ordy as an expansion of the intestine. The 

 intestine proper forms several bends, and has extremelj' 

 thin walls. The livei-, which is of a nankeen-yellow, 

 consists of one single piece, without 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 wanting. The kidneys are triangular, and lie 

 with the broad end in front, jjosteriorly tapering to a 

 point. The urinary bladder is large, clear, thin-walled 

 and obovate. The peritoneum is white 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 bii'ds. They 

 are situated somewhat behind the middle of the ab- 

 dominal cavity. 



Of the peculiarities of the skeleton we 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 (as nrbitnspliciioideum), though thin. The 

 operculum and preoperculum are considerably reduced, 



