ANIMAL PHYSIOLOGY. 



hearing would bo wanting to them. Yet, strange to say, whilo 



1, tint Hunt t hearing in innoct* in still ondetermined. 



j"iutod appendages of the head, have been 



l..dknl uj. -:i as tho neat of the sense of hearing:, but 



io baHol joint or tho terminal one in a matter 



in. I in ono instance it wan supposed to have been 



:it tho hip joint of tho front pair of legs a singular 



!, it must bo conf eased. To show tho difficulty of do tor- 



matters, wo have {riven a sketch of tho external 



.if two supposed organs of sense in tho common lobster. 



The lit protuberance, with a holo through the shell at 



tho summit, \\hirh i> closed by a nn-mliriiii 1 , beneath wh. 



little bag of llui.l with a nerve running to it, which is found on 



problems may be thus propounded : What itroctur**, in the 

 nh, are the representatives of the ossicles of the tympanum 

 called the hammer (malleus) and anvil (incut) in the "^Bir-ml ? 

 To this question an answer U given by BOOM of onr best 

 anatomists which is almost startling from its strangeness, bat 

 hi.-ii, on further examination, has much to support it. These 

 anatomists affirm that the two bones, which form the joint of 

 the lower jaw in the fish, are the representatives of the hammer 

 and anvil, taken out, so to speak, of the ear-dram, much enlarged 

 and np|>lii to quite a different purpose. Such question* as 

 these require much research to determine them, and are only 

 mentioned hero to give a slight insight into the difrhH+W found 

 in unravelling tho plan of Nature, though there U undoubtedly 

 a plan in all her works. 



I. BONE CONTAINING THE EAR OP A BABBIT. II. EAR-BONE OF THE WHALEBONE WHALE, ONE-FOURTH NATURAL SIZE. ITL INTERVAL EAII 

 OF A BIRD. IV. EAB OF A COD. V. EAB-STONB OF COD. VI. UNDER SIDE OF LONG ANTENNA OF A LOBSTER. Vn. UFFER SIDE OF 

 SHORT ANTENNA OF A LOBSTER. 



Et to Nos. in Figs. II. 1, tympanic bone ; 2, its point of attachment to the skull. III., IV. 1, cochlea; 2, vestibule : 3, oral hole ; 4, 5, G, 

 semi-circular canals; 7, sack of ear-stone. VI., VII. 1, organs of sense. 



the Tinder side of tho first joint of the first, or long, pair of 

 antennae, has been long considered the organ of hearing. Now, 

 however, the opinion seems to prevail that this is an organ of 

 Email, while that found opening on tho upper side of the first 

 joint of tho second, or short, pair of antcnnse, is now thought to 

 bo the true car. In scorching for the ear, the presence of hard 

 bodies suspended by threads in a sack containing liquid, and 

 capable of striking upon a nerve filament, is considered as 

 characteristic and indicative of an ear, just as the expansion of 

 a norve in front of black pigment and behind a transparent 

 membrane is thought to denote an eye. The first-named 

 structure is found in the organ of the lobster lost described, 

 but not in the other. 



It will be eeen that much remains to be mode out about the 

 ear, and the subject is extremely difficult to study. Indeed, 

 some of the most perplexing problems of the comparative 

 anntomiat peem to be associated with the ear. Ono of tho 



The temporal bones which, in man, lodge tho internal and 

 support tho external ears, and besides these functions, close in 

 the brain-case at the sides, send out strong buttresses forward to 

 strengthen the bones of the face, ud others to sling tho throat 

 bones upon, and also give attachment to the lower jaw ore the 

 most difficult bones in the body to describe and remember. 

 Many vessels and nerves enter them by numerous holes, and 

 these subdivide and find their way out in such strange ways, 

 that many a poor medical student has trembled when, in 04. 

 examination, a temporal bone has been placed in his hand. 

 These bones are no doubt composed of many elements which are 

 distinct in reptiles, birds, and fish: but, to moke confusion 

 worse confounded, the student of comparative anatomy finds on 

 the ono hand that Professor Owen divides the bone into at least 

 nine elements, and gives them names according to his theory ; 

 on the other Professor Huxley transposes all the relations, and 

 christens them by new names. 



