94 PARKER— A CRITICAL SURVEY OF 



large otoliths in the sacculi of Cynoscion are pinned off against the 

 non-nervous walls of these organs, responses to sounds largely cease, 

 whereas a destruction of the utriculi and semicircular canals does 

 not affect hearing. These observations support Piper's conclusions 

 (1906a, 1906&) based on experiments involving what were without 

 doubt the saccular otoliths. Thus, the sacculus, rather than the 

 utriculus, seems to have to do with hearing in fishes. In this con- 

 nection it is interesting to record the observations of Smith (1905, 

 p. 378) to the effect that in those sciaenid fashes that make drumming 

 noises the otoliths from the sacculi are exceptionally large, whereas 

 in Menticirrhus, a scisenid which does not drum, they are relatively 

 small, thus suggesting a relation of the sacculus to hearing as was 

 suspected by Scott (1906, p. 49). Without, therefore, putting too 

 great confidence in these somewhat fragmentary observations, it 

 seems probable that in the ears of the higher fishes where utriculus 

 and sacculus are well differentiated, the sacculus has to do with 

 hearing and the utriculus with equilibrium. 



The bearing of this conclusion on the functional interpretation 

 of the parts of the internal ear in the higher vertebrates must be 

 obvious. It points at once to the macula acustica sacculi as a pos- 

 sible organ of hearing. Whether, in mammals, for instance, this 

 saccular organ is concerned with hearing or not must, of course, be 

 settled by experiment (compare Richard, 1916), but so far as the 

 condition in fishes is concerned, it is not unreasonable to anticipate 

 an auditory function for it. Its function, however, must be very 

 different from that of the cochlear organ, for while the cochlea is 

 without much doubt the organ of the ear concerned with tone dis- 

 crimination, the macula acustica saccuh is probably at best only a 

 means of distinguishing between the presence or absence of sound, 

 including possibly its intensity. In this primitive way fishes prob- 

 ably hear, for it is unlikely, since they lack a cochlear organ, that 

 they respond in any differentiated way to differences of tones. 

 Their hearing is probably to be compared to the vision of the totally 

 color-blind, rather than to that form of vision in which colors are 

 discriminated. 



But the fish ear is not only primitive in itself ; it exhibits in its 

 various conditions several grades of proficiency. In not a single 



