THE EELS. 517 
All Eels, however, do not descend to the sea. It is by no means necessary 
to their existence to do so, and individuals may be confined in land-locked 
lakes and live indefinitely, growing, but in reduced ratio, year after year. 
Further, according to Jacoby, “there may be found in Comacchio and 
doubtless everywhere where Eels live in great numbers in brackish water 
along the coast, a peculiar group of Eels which” apparently ‘consists 
entirely of sterile females. These female Eels with ovaries present a very 
peculiar phenomenon ; when they are opened one finds, instead of the well- 
Leptocephalus brevirostris, Nat. size. Grassi. 
The same Leprocephalus at a later stage. Nat. size. 
Transition-stage or hemi-larva of the Eel. Nat. size. 
Young Eel (Elver) after the transformation. Nat. size. 
known yellowish-white, very fatty, cuff-shaped organ, a thin, scummy, 
slightly folded membrane, not at all fatty, often as transparent as glass, 
and of about the same proportional size as the so-called cuff-shaped organ. 
When this membrane is examined under the microscope, there may be seen 
in it eggs very transparent in appearance, with yolk-dots absent or with 
yolk-dots very small and few. This organ appears to be an abnormally 
developed ovary incapable of fertilization.” The Eels thus characterized 
present the other female features in an exaggerated degree. The flesh has 
an unusually delicate flavor, “ quite different from that of other Eels,” and 
“melts upon the tongue.” They can also be distinguished externally, “their 
