156 THE LARVA OF THE EEL, 
nant in his ‘‘ British Zoology” published in 1769. In the 1788 
edition of the ‘“‘Systema Nature” of Linnzus this fish was 
included under the name of Leptocephalus Morris. In 1818 
Colonel Montagu, having obtained some fresh specimens, 
described it under this name in the Memoirs of the Wer- 
nerian Natural History Society. 
Down to the year 1861 no doubt seems to have been ra sed 
as to the right of Leptocephalus Morrist: and its allies to rank as 
a distinct group of fishes, but in that year a distinguished 
German Naturalist, Professor J. V. Carus, suggested that 
they were merely larve or young immature forms of some 
other fishes, and three years later a Mr. Gill, an American 
Naturalist, came to the same conclusion, and further ex” 
pressed his opinion that L. Morvisi was the young of the 
Conger (Conger vulgaris. ) 
Dr. Giinther in his ‘‘ British Museum Catalogue of Fishes” 
published in 1870, supported Gill’s view both on anatomical 
grounds and from the point of view of geographical distribu- 
tion; he, however, differed from the American Naturalist in 
one important respect—Gill considered the Leptocephalus to be 
an ordinary larva which would in due course develop into a 
Conger; Dr. Giinther on the other hand believed it to be 
an abnormal larva, which, owing to some unfavourable con- 
ditions, had had its structural development arrested at an 
early period while still continuing to grow, and which was 
destined to die without ever attaining the characters of the 
mature ariimal. 
One point urged by Dr. Giinther in favour of his view was 
that he had seen specimens of the Conger not more than 4% 
inches long, while specimens of Leptocephalus Mornsi frequently 
exceed 6 inches in length. 
Both Gill’s and Ginther’s identifications were based entirely 
on anatomical and other resemblances which could not settle 
the difference between their views; but in 1886 a French 
Zoologist, M. Yves Delage, proved the American Naturalist’s 
