MR. T. SOUTHWELL ON THE REPRODUCTION OF THE COMMON EEL. 267 
we know now that the Common Eel develops a bridal coloration 
or 1 mating habit,’ which is chiefly characterised by the silver 
pigment without trace of yellow, and by the more or less black 
colour of the pectoral fin, and finally by the large eyes.” 
Petersen’s inference that this was the bridal coloration, was 
derived from the largely developed state of the reproductive 
organs, and by their ceasing to take nourishment. “ Here,” says 
Dr. Grassi, “Petersen’s observations cease and mine begin. The 
same currents at Messina which bring us the Leptocephali, bring 
us also many specimens of the Common Eel, all of which exhibit 
tho silver coloration, and not a few of them present the 
characters described by Petersen in an exaggerated condition, that 
is to say, the eyes are larger and nearly round instead of elliptical, 
whilst the pectoral fins are of an intense black . . . Undoubtedly 
the most important of these changes is that of the increase of the 
diameter of the eye, because it finds its physiological explanation 
in the circumstance, that the Eel matures in the depths of the sea.” 
We thus arrive at the last stage of the development of the Eel, 
which is not accomplished until it reaches the salt-water of the 
deep sea, and performs its appointed function of re-production. 
Dr. Grassi thus concludes his most interesting contribution to 
the life-history of this remarkable fish. “To sum up, Anguilla 
vulgaris , the Common Eel, matures in the depths of the sea, 
where it acquires larger eyes than are ever observed in individuals, 
which have not yet migrated to deep water . . . The abysses of 
the sea are the spawning places of the Common Eel : its eggs float 
in the sea water. In developing from tho egg, it undergoes 
a metamorphosis, that is to say, it passes through a larval form 
denominated Legtoceplialus brevirostris. What length of time 
this development requires is very diificult to establish. So far 
we have only the following data : — First, Amjuilla vulgaris 
migrates to the sea from the month of October to the month of 
January; second, the currents, such as those of Messina, throw 
up, from the abysses of the sea, specimens which, from the 
commencement of November to the end of July, are observed to 
be more advanced in development than at other times, but not 
yet arrived at total maturity ; third, eggs, which according to every 
probability belong to the Common Eel, are found in the sea from 
the month of August to that of January inclusive ; fourth, the 
