454 On the Metamorphosis of Syngnathus lumbriciformis. 



on the following morning a fifth and sixth, made their appear- 

 ance ; several were not hatched. The whole egg substance 

 exhibited itself in a half dissolved condition, separated itself, 

 together with the adherent cellular substance, from the body, 

 and fell in pieces. The fish died on the same day towards 

 the evening. I now sacrificed two of the young for observa- 

 tion, and endeavoured by constant renewal of the water to 

 retain the others alive, in order to observe their metamorphosis. 

 The experiment, however, did not succeed. On the seventh 

 day of their life they died one shortly after the other. What I 

 observed during the short time they lived was their rapid growth 

 from scarcely three Swedish lines in length to five ; otherwise 

 no change occurred in them. 



In the annexed plate, M. W. v. Wright has figured with his 

 accustomed accuracy one of these young. PI. XII. fig. 1. is a 

 side view of it magnified. Fig. 2. from above, and the interme- 

 diate small figure indicates the natural size. The entire body 

 is white and transparent, so that the vertebral column and the 

 intestinal canal in the ventral cavity appear through. The 

 head, very large in proportion to the rest of the body, oc- 

 cupies about a sixth of its whole length, has true and di- 

 stinct eyes, and also the turned-up snout which characterizes 

 S. lumbriciformis. The length of the snout in proportion to the 

 other parts of the head is larger in the young than in the old 

 fish. It is also worthy of remark, that while the border of the 

 gill covering in all older Syngnathi is connected by a mem- 

 brane, and the common epidermal covering with the rings of the 

 shoulder, and leaves behind at both sides of the neck merely 

 a small aperture by which respiration is effected, the young 

 have the same border of the operculum entirely free, by which 

 the gill apertures are greater than is generally the case in fish. 

 Fig. 2. shows it quite distinctly. The anal aperture, which 

 occupies its right position relatively to the dorsal fin, lies, 

 however, somewhat nearer to the caudal extremity than in old 

 individuals, i. e. a portion nearly equal to half the length of 

 the body. This aperture in the young fish is more distin- 

 guished by the projecting posterior angle which the ventral 

 line forms at this place. The scale plates which in the form 

 of rings cover the whole body in the old fish appear not yet 



