672 FISHES. 



none have been found in South America or the west coast 

 of ISTorth America and West Africa. The following are the most 

 note- worthy : — The common European species (A. anguUla) is 

 spread over Europe to 64° 30' lat. N., and all round the 

 Mediterranean area, but is not found either in the Danube or 

 in the Black and Caspian Seas ; it extends across the Atlantic 

 to North America. The form of the snout varies much, and 

 some naturalists have believed that specimens with a broad 

 and obtuse snout were specifically distinct from those with 

 pointed snout. However, every degree of breadth of the snout 

 may be observed ; and a much safer way of recognizing this 

 species, and distinguishing it from other European Eels, is 

 the forward position of the dorsal fin ; the distance between 

 the commencement of the dorsal and anal fins being as long 

 as, or somewhat longer than, the head. Eels grow generally 

 to a length of aljout three feet, but the capture of much 

 larger examples is on record. Their mode of propagation is 

 still unknown. So much only is certain that they do not 

 spawn in fresh water, that many full-grown individuals, but 

 not all, descend rivers during the Avinter months, and that 

 some of them at least must spawn in brackish water or in deep 

 water in the sea ; for in the course of the summer young 

 individuals from three to five inches long ascend rivers in 

 incredible numbers, overcoming all obstacles, ascending verti- 

 cal walls or floodgates, entering every larger and smaller 

 tributary, and making their way even over terra firma to waters 

 shut oft' from all communication with rivers. Such immigra- 

 tions have been long known by the name of " Eel-fairs." The 

 majority of the Eels which migrate to the sea appear to return 

 to fresh water, but not in a body, but irregularly, and through- 

 out the warmer part of the year. No naturahst has ever 

 observed these fishes in the act of spawning, or found mature 

 ova ; and the organs of reproduction of individuals caught 

 in fresh water are so little developed and so much alike, that 



