THE EEL FAMELY. 435 



ignorance has attempted to cloak itself, in connection with the 

 reproduction of the eel. 



In some parts of Britain even educated persons will assert 

 in good faith that the young eel owes its existence to the 

 spontaneous vitalising of stray horse-hairs, and Jacoby mentions 

 that Sardinian fishermen cling to the belief that a certain 

 beetle {Dytiscus Roeselii) is the progenitor of the eel, and they 

 therefore call this beetle " mother of eels," and the same origin 

 has been actually upheld in writing by Cairncross, who gives 

 an account of the birth of two or three hair- eels from one 

 of these insects, resulting in the death of the parent. Two 

 of the offspring he claims to have kept for two years till they 

 were 8^ inches long. He admits having lost sight of them for 

 nine months ! 



The eel, like other animals, is often infested with thread- 

 worms, and this has given rise to another assertion that it is 

 viviparous ; this statement is even mentioned and corrected by 

 Aristotle. He remarks : ' Eels are not produced from sexual 

 intercourse nor are they oviparous, nor have they ever been 

 detected with semen or ova, nor when dissected do they appear 



to possess either seminal or uterine viscera It is plain, 



therefore, that they are not produced either from sexual 

 intercourse or from ova. Some persons have thought that they 

 were productive, because some eels have parasitical worms and 

 they thought that these became eels. This, however, is not the 

 case, but they originate in what are called the entrails of the 

 earth, which are found spontaneously in mud and moist earth. 

 They have been observed making their escape from them and 

 others have been found in them when cut up and dissected. 

 These originate both in the sea and in rivers where putrid 

 matter is abundant ; in those places in the sea which are full of 

 uci, and near the banks of rivers and ponds, for in these places 

 the heat causes much putridity. This is the mode of genera- 

 tion of eels.' It is hardly clear what the ' entrails of the earth ' 

 means; how near to the truth Aristotle may have been will 

 be seen later. 



Leeuwenhoek, as late as 1692, describes the urinary bladder 

 of the eel as a uterus, and parasitic worms therein as the young. 



28—2 



