382 G. B. GRASSI. 
The facts which I have stated demonstrate that the eel goes 
through a metamorphosis, and that Leptocephalus brevi- 
rostris is its larva. Some further considerations remain to 
be given, although I believe that zoologists will not consider 
the question still an open one after the record of facts given 
above—facts which any one may verify by examining the 
material which is preserved in my hands. Many to whom I 
have related my discovery of the history of the common eel 
have objected that eels are found almost everywhere, whilst 
Leptocephalus brevirostris is limited to Messina. In 
reply, I must say that, first of all, it is not true that Lepto- 
cephalus brevirostris is limited to Messina; secondly, that 
at Messina there are special currents, which tear up the deep- 
sea bottom which everywhere else is inaccessible; thirdly, 
although it is true that on the coasts of many countries where 
Anguilla vulgaris is found, no one has ever seen a Lepto- 
cephalus brevirostris; it is also true that in no country, 
not even in those where eels are abundant, has anyone ever 
seen an eel of less than 5 cm. in length. Since it has to be 
admitted that no one knows the eel before it arrives at the 
length of 5 cm., there is no greater difficulty in supposing that 
during this unknown period the eel passes through a Lepto- 
cephalus stage than in supposing that it does not do so. The 
critical study of the literature of this subject, and a great many 
continued observations, have occupied me for many years, and 
have been undertaken just in those places where young eels 
are to be found. They enable me, from my own studies, to 
affirm with assurance that young eels with the definitive adult 
form do not exist of less than 5 cm. in length. 
From the study of the memoir of Raffaele on pelagic eggs, I 
have come to the conclusion that the eggs of his undetermined 
species No. 10, having a diameter of 2:7 mm., and differing 
from all the others in the absence of oil-globules,! must belong 
to the Anguilla vulgaris, because from them Dr. Raffaele 
1 Renewed researches have convinced me that this egg is that of An- 
guilla vulgaris. There is, however, another egg belonging to an unde- 
termined Mureenoid which is devoid of oil-drops, and can easily be confused 
with the true eggs of Anguilla. 
