REPRODUCTION AND METAMORPHOSIS OF COMMON EEL. 37] 
The Reproduction and Metamorphosis of the 
Common Eel (Anguilla vulgaris).' 
By 
G. B. Grassi, 
Professor in Rome. 
Four years of continual researches made by me in collabo- 
ration with my pupil, Dr. Calandruccio, have been crowned at 
last by a success beyond my expectations,—that is to say, have 
enabled me to dispel in the most important points the great 
mystery which has hitherto surrounded the reproduction and 
the development of the Common Eel (Anguilla vulgaris). 
When I reflect that this mystery has occupied the attention of 
naturalists since the days of Aristotle, it seems to me that a 
short extract of my work is perhaps not unworthy to be pre- 
sented to the Royal Society of London, leaving aside, however, 
for the present, the morphological part of my results. 
The most salient fact discovered by me is that a fish, which 
hitherto was known as Leptocephalus brevirostris, is the 
larva of the Anguilla vulgaris. 
Before giving the proofs of this conclusion I must premise 
that the other Murenoids undergo a similar metamorphosis. 
Thus I have been able to prove that the Leptocephalus 
stenops (Bellotti), for the greatest part, and also the Lepto- 
cephalus morrisii and punctatus belong to the cycle of 
evolution of Conger vulgaris; that the Leptocephalus 
haeckeli, yarrelli, bibroni, gegenbauri, kéllikeri, and 
many other imperfectly described by Facciola, and a part of 
the above-named Leptocephalus stenops of Bellotti, 
belong to the cycle of evolution of Congromurena my stax; 
that the Leptocephalus tenia, inornatus, and dia- 
1 From the ‘ Proceedings of the Royal Society,’ November, 1896. 
