On the Mode of Propagation of the Common Eel, read at the Annual 
Meeting of the Cotteswold Club, on Tuesday, May 4th, 1886. 
By Francis Day, C.I.E., F.L.S., ete. 
Among the many forms of fishes which are resident in fresh 
water, there is scarcely one that has been the origin of so much 
controversy as the common Hel, Anguilla vulgaris. Subdivided 
into three (1) species, in accordance with the sharpness or blunt- 
ness of its snout, or the amount of.development occurring in 
its lips, it is not surprising that some systematists have been 
slow to accept the correctness of the opinions of Field Natural- 
ists and Fish Culturists, that these different peculiarities are 
merely evidences of sex, or the result of accidental causes. I 
shall, without further discussion on this point, consider that it 
has been abundantly proved that in this country we merely 
possess a single species of Hel pertaining to the genus Anguilla, 
and that it is a catadromous form, or one which migrates to 
the mouths of rivers and the sea when desirous of continuing 
its kind. 
If, however, the many varieties of this fish have been the 
cause of countless disputes among systematists, still greater 
have been the differences of opinion respecting its mode of 
propagation, and this even from the earliest times. ARISTOTLE 
imagined that they were spontaneously generated, unless they 
spring from mud or slime, adducing as a reason that no adult 
Kel had ever been seen which contained either hard or soft roe. 
This gave occasion to one of the Grecian poets to observe that, 
since all children whose paternity was doubtful were popularly 
ascribed to Juprrer, possibly he ought likewise to be looked 
upon as the progenitor of the Hels. Privy had an idea that 
the fragments of the skin of the parent, which had been rubbed 
