of the Fishery Board for Scotland. 



211 



river eels have their settled spawning-places on mud banks in the sea, 

 not near the coast. 



It has sometimes been maintained that the eel was viviparous, but 

 such assertions have been founded on the discovery in the eel of thread- 

 worms. In this connection, Robin* says that 'the disposition of the 

 ' male organ permits of the understanding that these might be coupling, 

 1 and the possibility of the introduction of the sperm of the male into the 

 ' cloaca of the female. But the absence of the oviduct in the eel renders 

 1 impossible the arrival of the sperms as far as the ovaries, and from there 

 ' to the ovules. Valenciennes states, on the authority of the fishermen, 

 ' that the eels spawn while in contact, two to two, or with the interlacing 

 ' of several individuals of different species. But no one has anatomically 

 ' proved — 1st. If there had been an individual provided with testes ; 2nd. 

 ' If in the interlacing of several eels, there had been a mixture of pim- 

 1 peneaux with the ordinary female eels. These facts, which it would be 

 ' easy to prove, still remain an open question. The same remark applies 

 ' to the assertions of certain persons, as to the eels, male and female, 

 1 rolling themselves up in a ball, the size of a man's head, and allowing 

 ' themselves to roll to the sea for the purpose of spawning.' In Sardinia, 

 Jacoby mentions, the fishermen cling to the belief that a certain beetle, 

 the so-called water-beetle, Dytiscus Roeselii, is the progenitor of the eel, 

 and they therefore call this beetle 1 mother of eels.' A similar belief is 

 stoutly maintained by Cairncross, j who gives a very circumstantial account 

 of the birth of the eels from a beetle ; he does not mention the species of 

 the beetle. He observed, on many separate occasions, these beetles give 

 birth, at the expense of their lives, to one or two hair eels. He claims to 

 have kept two of the eels born of a beetle for two years, and at this age 

 they measured 8J inches in length. He admits, however, that he lost 

 sight of them for a period of nine months. 



There can be no doubt that the eel spawns just as other fishes do. 

 Whether the egg is pelagic or not, is unknown. It is well known that 

 many fishes which have demersal eggs, deposit their spawn during the 

 winter months. Pelagic ova are rarely found in the Firth of Forth until 

 late in January, and during that month and February they are very few 

 in number. If the eel has a pelagic egg, it is remarkable that it has not 

 been captured in the tow nets of the ' Garland.' In December and 

 January, during which months it appears probable that the eel spawns, 

 the tow net is regularly used in the Firth of Forth. The large number of 

 migrating eels, and the great shoals of fry, lead one to infer that the ova 

 must be shed in immense numbers. It is not probable that a pelagic 

 egg, present in such quantities in the Forth, would have eluded capture 

 up till the present time. One must conclude that, if the egg is pelagic, 

 it must be desposited out at sea. Professor M'Intosh thinks it probable 

 that the eels deposit their ova on or in the sand, somewhat after the 

 fashion of the sand eel. The little transparent eel is sometimes dug up 

 out of the sand. The attendant at the Laboratory has on two occasions 

 when in search of sand eels dug up the little eel. Although the ripe 

 eggs of neither the conger nor common eel are known, ' Grassi and Calan- 

 ' druccio state that they have been able from their own observations to 

 ' confirm with complete certainty the suggestion of Raffaele that certain 

 ' pelagic eggs described by him belong to the family of the Muraenidae.'J 



What becomes of the eels after spawning? According to several 

 writers the eels never return to fresh water, but disappear altogether. 



* ' Les Anguilles males coniparees aux femelles,' Journal de V Anatomic, etc., 1881. 

 t Cairncross, 'The Origin of the Silver Eel,' 1862, G. Shield, London. 

 % Cunningham, 'The Larva of the Eel,' Journal of Marine Biological Assoc., 

 New Series, vol. iii., No. 4, 1895. 



