THE EEL FAMILY. 441 



black, while in some the anterior margin of the gill-slit is of 

 the same colour. 



Jacoby, whilst examining female eels, found certain indi- 

 viduals whose reproductive organs were very undeveloped, and 

 which showed distinct outward differences from the ordinary 

 female. These he regards as sterile females. The following 

 description is taken from his article on the ' Eel Question' : — 

 ' In Comacchio, and doubtless wherever large masses of eels live 

 even in brackish waters, near the sea coast, a certain variety of 

 eel exists, which I found were barren females of the common 

 species. They are female eels whose ovaries show an entirely 

 anomalous condition. On opening such an eel, one finds, 

 instead of the well-known yellowish white and very fatty 

 frill-like organ, a frothy thin band without any fat and having 

 few folds, often as transparent as glass, otherwise of the same 

 length and breadth as the frill organ, varying of course accord- 

 ing to the size of the eel. If this band be examined under the 

 microscope, the eggs appear transparent, containing but very 

 few grains of yolk, or none at all. The band therefore appears 

 an anomalously developed ovarium. The outward distinguish- 

 ing marks of the barren females, which I found of all lengths 

 up to 70 cm. (28 inches), are very striking. They show all the 

 above-mentioned distinguishing marks of the female intensified. 

 Their snout is broader, often — especially the point of the lower 

 jaw — extraordinarily broad, the dorsal fin generally higher, the 

 eyes decidedly smaller, in larger specimens astonishingly small, 

 and the colour is generally a light yellowish-green ; further the 

 back is of a lighter colour, and the belly of a brighter yellow than 

 in the common female eels. In Comacchio, this eel is called 

 'pascuite^' By the term 'pascuite,' however, the fishermen 

 understand immature normally developed eels, as well as the 

 sterile females. The sterile females grow as large as ordinary 

 females, but never leave the brackish waters.' According to 

 Comisa, the barren female may probably, under certain con- 

 ditions, develop into a normal female. 



What little we know concerning the eggs themselves has 

 been gathered from an examination of ripe or nearly ripe 

 ^ The ' pascuite ' appears to be identical with the yellow eel of Petersen. 



