The appearance of the male yellow eels (plate II, fig. n) is in all essen- 

 tials like that ol' the feiiiales. I have beeu uiiable to lind any t;xiod exteriial 

 cliaracters except in the size, which can sei\e to distingnisli yellow males 

 l'rom yellow l'eniales. Wheu authors as MnJiiiis and Heincle (Die Fiselie der 

 Ostsee«) sjieak ol' a differenee in the size ol' the eyes ol' males and l'emales, 

 this holds good of silver eels ouly, and these only seem also <o have l)een the 

 hasis of their pictnres. Ptohw (Journ. de l'Anat. et de la Phys. f). Ser. ISSl«) 

 also seems to know males iu breeding-dress only (»pimpenaux«). L. Jarohi/: 

 »Der Fischfang in der Lagune von Comacchio. 1880. (Berlin.)« mentions, ]>. 

 40, sevei'al external differences between males and females, aniong wliich 

 however he partienlarly lays the stress on tlie difference in sizi' as ilie most 

 important one. (Moi-e of tliis under »The Silver Eels«). He then mentions that 

 the fip nf the stwiif if hroader in the females than in tlie males; that this 

 character is (piite unreliable will be seeu immediately wheu we look at tig. (j, 

 jilate II, uor have I ever found it confirmed by my investigatious; to be sure 

 the males may sometimes be ver}' sharp-nosed (tig. 7, jtlate II), but as to the 

 form of the suont and the interorbital spaee there is so great variation within 

 both sexes, that it can scarcely afford any reliable character. — Javohy then 

 mentions that the females at Comacchio differ from the males iu their colour, 

 and that »ich fand zuweilen vollig broucefarbeue Aale, stets mit dem 

 Si/rsli'schen Organ«; I have the impressiou of his descriptiou, loc. cit. |). ;")(), 

 where he says »der voUstandig ausgebildete weibliche Aal . . . llaucli 

 weisslich-gelb, wenig oder kein MetaUglauz . . .«, that the emigrating i'emale 

 eels he has seen are not fully developed silver eels, but that on the~othcr 

 band, the males may be so. In our seas the fully developed i'emale eels 

 have a strong metallic lustre, and are not in the least inferior to the males 

 in this regard. 



His next distinctive mark between male and female is the lirii/ht 

 of Ihf (loisal tin. It is very ])Ossible tluit there is a slight difference liere; 

 it seejns so. Whether Jacohi/ has here compared yellow males to yellow 

 females, or whether there maj' possibly be any difference in this regard 

 between the Italian and the Danish eel, I do not know; ))ut to this exter- 

 nal character I have beeu unablc to attacii much importance, especially 

 as it is not easy to measure accurately. 



At last. and r^'; Icnt^t (ij)plir(iJ>lr as a distincti\'e mark between the sexes, 

 he mentions the si.rf of Ilic n/rs: tlio i'casdu ol' this is (>videutly tiiaf he 

 has had both yellow males and silvei' males lu'l'Drc liiin, the fiirnicr witli 

 siiiall eves the latter with large ones. 



