80 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



there is such a number of false beliefs and ridiculous fables. Some of 

 these may be put aside as fabrications ; others were, probably, more or 

 less true, but all the opinions concerning the propagation of the eel may 

 •be grouped together as errors into three classes : 



" (I.) The beliefs which, in accordance with the description of Aris- 

 totle, account for the origin of the eel not by their development from 

 the mud of the earth, but from slimy masses which are found where the 

 eels rub their bodies against each other. This opinion was advanced 

 by Pliny, by Athenseus, and by Oppian, and in the sixteenth century 

 was again advocated by Rondelet and reiterated by Conrad Gessner. 



"(II.) Other authorities base their claims upon the occasional dis- 

 covery of worm -like animals in the intestines of the eels, which they 

 described, with more or less zealous belief, as the young eels, claiming 

 that the eel should be considered as an animal which brought forth its 

 young alive, although Aristotle in his day had pronounced this belief 

 erroneous, and very rightly had stated that these objects were probably 

 intestinal worms. Those who discovered them anew had no hesitation 

 in j)ronouncing them young eels which were to be born alive. This 

 opinion was tirst brought up in the middle ages in the writings of 

 Albertus Magnus, and in the following centuries by the zoologists Leu- 

 wenhoek, Eisner, Eedi, and Fahlberg -, even Linnseus assented to this 

 belief and stated that the eel was viviparous. It is but natural that 

 unskilled observers, when they open an eel and find inside of it a greater 

 or smaller number of living creatures with elongated bodies, should be 

 satisfied, without further observation, that these are the young of the 

 eel ; it may be distinctly stated, however, that in all cases where eels of 

 this sort have been scientifically investigated, they have been found to 

 be intestinal worms.* 



"(III.) The last group of errors includes the various suppositions that 

 eels are born not from eels, but from other fishes, and even from animals 

 which do not belong at all to the class of fishes. Absurd as this sujiijo- 

 sition, which, in fact, was contradicted by Aristotle, may seem, it is 

 found at the present day among the eel-catchers in many parts of the 

 world. 



" On the coast of Oermany a fish related to the cod, Zoarces vivipariiSy 

 which brings its young living into the world, owes to this circumstance 

 its name Allmuter, or eel mother, and similar names are found on the 

 coast of Scandinavia." 



" In the lagoon of Comacchio," continues Jacoby, " I have again con- 

 vinced myself of the ineradicable belief among the fishermen that the 

 eel is born of other fishes ; they point to special differences in color, 



* It is very strange that an observer, so careful as Dr. Jacoby, should denounce in 

 this connection the well-known error of Dr. Eberhard, of Eostock, who mistook a 

 species of zoarces for an eel, and described the young, which he found alive within 

 the body of its mother, as the embryo of the eel. In Jacoby's essay, p. 24, he states 

 that the animal described by Eberhard was simply an intestinal worm, an error which 

 will be manifest to all who will take the pains to examine the figure. 



