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ANNALS NEW YORK ACADEMY OF SCIENCES 



more than a few hours. The specimen in question, I may mention, was 

 in perfect condition when taken. It was noticed in the bag of a seine, — '■ 

 by accident rather than by design, — for had the fish not been actively 

 moving at a particular moment, it would have escaped unnoticed on 

 account of its glassy transparency. It proved to be hardy and lived in 

 an aquarium for over three weeks, during this time undergoing its 

 metamorphosis. 



September 13. Larva (Fig. 1) almost colorless, even in light of dif- 

 ferent intensities; it is rarely at rest; it is apt to swim rapidly and with 



Pig. 1. — Eel larva. September 13. About natural size 



a kind of lurching movement. When advancing slowly, its height, which 

 insures contact with a large surface of water, allows it to move with 

 precision, — in the sense that a pencil held vertically in the first in-bent 

 curve of the fish's body will not be touched by the fish as it advances, — 

 in other words, that the fish does not show lost or slipping movements. 



When resting, the young fish arranges itself 

 in irregular vertical coils, thus probably 

 keeping its balance. When disturbed 

 (snout touched with a pencil point), the 

 fish retreats tail foremost, the head remain- 

 ing passive : if disturbed again, the head 

 will be quietly drawn back, the motion 

 starting as before with a withdrawal of the 

 tail and hinder trunk. If disturbed repeat- 

 edly, however, the fish will either swim 

 about actively or draw itself into a close 

 coil (Fig. 2). This position, however, it will sometimes assume without 

 artificial stimulus, e. g., after it has become "tired" swimming around 

 the wall of a circular jar. Leptocephalus from time to time secretes con- 

 siderable mucous : this remains attached but is finally "brushed off" (in 

 a mass) at the tail end of the body. Such a bit of slime will occasionally 

 be touched by the young eel when swimming about; it is evidently dis- 

 tasteful, for the young fish speedily frees itself, shaking its head in a 

 curiously energetic way. 



Pig. 2. — Eel larva. Retracted 

 position 



