FISHES. 341 



They have no external ear, at least, unless this name can be given 

 to a little cavity, sometimes slightly turned into a spiral form which 

 is anterior to the species of fenestra ovalis in the ray ; a cavity entirely 

 hidden vmder the skin. Bony fishes have neither this cavity, nor 

 even any fenestra ovalis : some amongst them, as the lepidoleprus 

 and certain mormyri, have only at the cranium openings stopped by 

 the skin, by which the vibrations of the ambient liquid may be imme- 

 diately conducted to the labyrintli. In others, such as the myri- 

 pristes, the cranium is opened below, and its orifice is closed by a 

 membranous septum to which the air bladder adheres ; but these com- 

 munications are very different from that which takes place through 

 the medium of the tympanum, and still more that which takes place in 

 the eustachian tube. 



The fishes are in fact deficient of the tympanum and its small bones, 

 as also of the eustachian tube. Those who are anxious to discover, 

 in the bones of the operculiun, the four small bones of the human ear 

 suddenly and prodigiously developed, could never have entertained 

 such an idea, except in conformity with the very dangerous system 

 which rejjresents that the osseous pieces ought to be found in the same 

 number in every head, and indeed they can offer no other reason in 

 its favour : neither the form, relations, nor functions of these bones, 

 nor the muscles which are attached to it, nor the neiTes which go it 

 can be forced into the comparison ; but this identity in the number of 

 pieces admits of so many exceptioni:. that it cannot serve consistently 



tains a good description of the ear, in the eel, whiting, pike, carp, cypiin, plaice, and 

 perch ; he mistook, however, for a meatus externus, certain foramina of the cranium, 

 which do not appear to have that destination. The figures originally annexed to the 

 memoir having been lost, there are none given in the publication. What he says of 

 the ray, is comprised in a memoir on the ear of reptiles presented in 1752, and pub- 

 lished in 1 755. 



Pierre Camper's investigations were made in 1761 ; they first appeared in the 

 Harlem memoirs in 1762. He addressed them in an amplified form to the Academy 

 of Sciences in 176? ; these were published in vol. vii. of the learned foreigners, in 

 1774. In these he describes especially the ear of the ray, cod, pike, baudroie, with 

 figures in his own, vague style. He added little to what Geoffroy had said before 

 him, except that he denied in too general a manner, the existence of the exterior 

 canal, and that he spoke of an organ which he called the tensor bursfe, and which 

 appears to be no more than an appendice, or rather a ligament stronger in the pike 

 than in many other fishes. 



In 1773, Kaelreuter has given, in the seventeenth volume of the Novi Commen- 

 tarii of Petersburgh, a description with figures of great accuracy and detail of the ear, 

 of two sorts of sturgeon, the common one, and the huzo. 



M. Monro states that he had not paid any attention to the ear of fishes till he had 

 heard of the observations of Camper ; but his information had reached him but 

 tardilly, for he had not heard of them till 1779. His own observations appeared in 

 his Anatomy of fishes 1785, accompanied by beautiful plates. He has described 

 better than either his predecessors, or successors, the external ear of the chondrop- 

 terygians; it is remarkably well seen in his collection of three treatises on the brain, 

 eye, and ear, published in Edinburgh in 1792. 



John Hunter asserts that he had discovered the internal ear of fishes as far back 

 as 17S6 ; but he did not publish his remarks, and then only as an extract, till 1786, 

 in his observations on certain parts of the animal economy. He acknowledges that 

 Geoffroy had preceded him on the ray. 



But the most exact description and finest drawings of the ear of fishes arc due to 

 M* Scarpa, in his Disqnisitiones de auditu et olfactv, printed at Pavia in 17S9. He 



