148 HEARING OF FISHES. 



the exact portion of sonorous intelligence be- 

 stowed on fishes by the construction of their 

 organs of hearing, is, amongst endless other exam- 

 ples, a proof of the exact but yet sufficient pro- 

 vidence or protection afforded to inhabitants of 

 the waters. There is an especial sac of calcareous 

 pulp given to skates and some other cartilaginous 

 fishes, in the place of dense ossicle ; apparently 

 intended to respond to the movements of sand and 

 muddy strata, on which they are doomed to exist. 

 And it is remarkable that the sturgeon has its 

 auditory ossicle, consisting partly of hard sub- 

 stances, and partly of calcareous pulp. In the 

 whale tribe, aerial thunder issues from their lungs, 

 and the booming of their voices is well adapted 

 to convey intelligence of distances to each other, 

 when parted by ice-islands ; while their organs 

 of hearing, adapted by filling the tympanum with 

 water, become hydrophonic organs, and tell the 

 distant collision of stones, of rocks, and icebergs." 



Herb. If fishes hear if these philosophical 

 investigations of so eminent an anatomist are to 

 be regarded, what becomes of Mr. Ronalds' ex- 

 periment ? 



Theoph. In a work called " The Catalogue, 

 &c. of the Royal College of Surgeons, vol. 3, pt. 

 ], p. 135, et seq. (which also contains Sir A. 

 C.'s ideas, together with drawings of several 

 kinds of these ossicles), is to be found a paper 



