of Syngnathus lumbriciformis. 453 



eggs were already so far advanced in development, that the 

 embryons might be plainly distinguished with the lens ; but 

 in the course of a few days the outer membrane became so 

 opake, that the changes, going on within, could not be observed 

 any further ; and since for my purpose I merely had in view 

 and waited for the hatching of the young, I would not venture 

 to disturb the fish and to deprive him of any of the eggs for 

 closer examination. 



After six days my little fish was evidently exhausted, and the 

 eggs began in many places to have a changed morbid appear- 

 ance, so that I entertained some fear for the result. However, 

 it still lived for some days, and as, on the morning of the 

 ninth day of its imprisonment, I performed the usual exami- 

 nation, I was agreeably surprised to find at the surface of the 

 water three hatched young. They swam in an erect position, 

 very little concerned about one another, and had still less to do 

 with the father, who lay quite still at the bottom. Through 

 the whole forenoon I constantly watched all their motions, 

 but could not perceive the least inclination in them to ap- 

 proach or hold on to the father, nor did he pay them the least 

 attention ; in a word, they were all strangers to one another. 

 Somewhat displeased at this coldness of theirs, which destroyed 

 beforehand the whole of my projected theory, I took a lens 

 and observed the young as they were swimming freely about 

 in the water. To my great astonishment I then first perceived 

 that they were provided with locomotive organs quite dissi- 

 milar to those which the parents possess. The entire tail was 

 surrounded by a fin-like membrane, and pectoral fins were di- 

 stinctly perceivable, which were in a constant vibratory mo- 

 tion, as in the marsupial pipe-fish. As none of our Ophidii 

 in their complete development possess any trace of pectoral 

 fins, and are without caudal fins, this discovery that these 

 organs occur in them in their young state came quite unex- 

 pectedly upon me ; however the fact itself was clear and un- 

 deniable. Hence it follows, that these fish, like tadpoles, 

 lose their tail and throw off caudal and pectoral fins at a 

 fixed, but as yet unknown period ; a circumstance that has 

 hitherto never to my knowledge been observed in the fish 

 tribe. In the course of the afternoon, a fourth young, and 



