342 FISHES. 



with strict logic to prove another proposition, being itself in a state of 

 doubt. 



With respect to those who have thought that they beheld in the 

 vast and quintuple communication of the branchiae with the mouth, a 

 development of the eustachian tube, they have not even sought to sup- 

 port their system or any sort of resemblance in the number and struc- 

 ture of the parts. 



There would have been something plausible to alledge in favour 

 of M. Weber's idea; for it went to show the analogues of the bones 

 of the ear in the osseous species which are placed at the side of 

 the first vertebrae, and which support the air bladder in the cyprins 

 and silures. Indisputably these osseous pieces as we have seen else- 

 where, have a direct communication with the labyrinth; but this con- 

 nection is not at all like that of the little bones of the ear in the 

 higher animals ; and though it were demonstrated that they partici- 

 pate in the functions of the organ of hearing, still they do not the less 

 remain, as M. Geoffrey has proved, simple dismemberments of .the 

 transverse apophyses of the first vertebrae. 



Analogy does not render it otherwise likely that we should have 

 bones necessarily in the fishes, since we see these bones degenerating 

 in number and volume, from the quadrupeds even down to the sala- 

 manders, and the sirena, where they are reduced to a single small 

 plate which represents the last half of the stapes. 



there gives a drawing from nature of the ear in the ray, baudroie, and pike. He 

 erroneously denies the external communication, discovered by Munro, in the ray. 



In the same year 17S9, M. Comparetti published at Padua, his observations on 

 the internal ear, in which he carefully describes, and represents accurately, though 

 not elegantly those of the ray, of the angel fish, sphinax, mustelus, the sturgeon, of 

 the tunny, the eel, the plaice, the pike, the denzelle, the carp, and gudgeon. 



It is from the researches of these authors, and those which I myself have made 

 that I have described the ear of fishes in my Comparative Anatomy. I have added 

 some facts relative to the sturgeon, the moon-fish, to the distribution of the 

 nerves, &c, and I should not suppose that this description, in as much as it is a 

 general one would require to undergo any modification. 



But in a latin work, printed at Leipsic in 1820, on the ear of man and animals, M. 

 Em. Henri Weber has given interesting details on this department of fishes, with very 

 clear descriptions, and with very fine and very faithful figures ; he has there offered an 

 entirely new hypothesis respecting the small bones which adhere to the first vertebrae 

 of the spine in the cyprins, silures, and cobites, which have been regarded to the 

 present time as exclusively appropriated to the swimming bladder, but which M. 

 Weber has shown to bear some relation to the ear of fishes. This leads him to 

 believe that they represent the small bones of the tympanum in man and the higher 

 animals, and not only these bones but the swimming bladder itself are amongst the 

 organs which are subsidiary to the ear. This opinion has been supported by M. 

 Bojaneus, in the Isis of 1818. 



M. Geoffroy has contended against it, at least in one sense, for he has made it 

 manifest that these small bones are more dismemberments of the first vertebras than 

 true bones of the ear, which he still continues to believe to be represented by the 

 opercular pieces. Since then I have discovered relations between the ear and the 

 natatory bladder of fishes, the existence of which had not been before suspected, and 

 in the myripristis. 



Lastly, there are some curious observations of M. M. Otto and Heusinger on 

 the apertures of the cranium in the lepidoleprus and the mormyr, through which 

 something of the vibrations of the ambiant element may be transmitted to the inter- 

 nal ear. 



