654 



NATURAL HISTORY OP AQUATIC ANIMALS. 



with food, not only those whieh were not sufficiently mature to migrate, but also a breed of Eels 

 which never goes to the sea, but remains throughout its entire life in the lagoons. 



"There may be found in Comacchio, and doubtless everywhere where Eels live in great num- 

 bers in brackish water along the coast, a peculiar group of Eels which, as far as I could deter- 

 mine, 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-known yellowish-white, very 

 fatty, cuff-shaped organ, a thin, scummy, slightly folded membrane, not at all fatty, often as trans- 

 parent 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. These sterile females, which I found 

 of all sizes, even up to the length of twenty-seven inches, present all of the acknowledged female 

 characters in great prominence and in an exaggerated degree: the snout is broader, and often, 

 especially at the tip of the under jaw, extraordinarily broad; the dorsal fins are, on the average, 

 higher; the eyes are much smaller, especially in large specimens, and the coloring is clearer; the 

 back of a clearer green and the belly yellower than in the normal female. The flesh of these 

 sterile females has a very delicate flavor, and quite different from that of other Eels. I was quite 

 astonished at the fine flavor when I tasted them for the first time in Comacchio. The flesh, as the 

 expression goes, melts upon the tongue. It is even possible to distinguish them while living, by 

 feeling them with the hand, their soft bodies being very different from the hard, solid, muscular 

 flesh of the others. 



"In Comacchio these Eels are called 'Pascinfi.' Coste called them 'Priscetti,' and defined 

 them to be those Eels which had not become ripe, but which were at least a pound in weight. The 

 name 'Priscetti' is, however, very incorrect, as I have become convinced by questioning the fish 

 inspectors and by hearing the conversations of the fishermen. 'Pasciuto' means 'pastured,' and 

 the fishermen understand by this, those Eels which do not migrate, but which remain through the 

 whole year feeding in the lagoons. They include, however, under this name, Eels of two kinds — 

 the sterile females already described, and the Eels which are not yet ripe, as well as the normal 

 females and supposed males whose period of migration is somewhat remote. This circumstance 

 is a cause of much difficulty to the investigator.' 



"The studies on the second point to be solved were of special interest, viz, the determina- 



1 It has been noticed by many early writers that there are certain Eels which never come to the sea — Eisso, in his 

 "Histoire Naturelle," tome 3, p. 198, and S. Nilsson, in his " Scandinavisk Fauna," tome 4, p. G63. The latter called 

 this variety " Grasaal," or Grass-Eel, and spoke of its yellowish-green coloration and the soft, delicious flesh. Strange 

 enough, both these writers spoke of the sharper snout of this Eel, and Eisso, who founded upon it another species, 

 Avgnilla acntirostris, described it as blackish above and silvery below. These descriptions apply in every particular 

 to the non-migratory Eel of Comacchio. Jacoby remarks that all the sterile females brought to him under the name 

 "Pasciuti" were distinguished by their broad snouts. The following tables were prepared at Comacchio. a gives 

 the total length of the body of the Eel; 6, the breadth of the snout between the nasal tubes, in millimeters. 



