46 AYERS. [Vol. VI. 



There are many instances of calculi formed in other parts of 

 the body, e.g. renal calculi, vesical calculi, pineal calculi, etc. 

 These calcareous concretions or crystals lie within the normal 

 cavities of these structures, or else within lymph spaces in their 

 walls ; they are abnormal, notwithstanding which they may exist 

 for long periods of time within these organs without causing 

 disturbance in the economy of the organ. 



So far as my reading extends, the older observers have never 

 put to themselves the question : Why do the otolithic crystals, 

 which are heavier than the endolymph, occupy the surfaces of 

 the hair cell areas, which as a rule project considerably above 

 the surface of the floor of the auditory chamber in which they 

 are found, and often in part lie on the side walls of the chambers 

 of the ear .'* 



Having greater specific gravity than the endolymph, the 

 crystals might be supposed to be always dropping to a lower 

 level until they reached the lowest, — the lagenar sac. 



That this displacement of the otoliths could easily follow is a 

 necessary consequence of the motions of the animal, giving 

 gravity the opportunity to pull the crystals to the lowest level. 



It is true that, generally speaking, the otolithic bodies occupy 

 the lower chambers, but they do not necessarily, and do not 

 usually lie in the lowest levels of these chambers, but defy the 

 law of gravitation by remaining perched on the top of the hair 

 cells or depending from the ends of the hair composing the 

 hair field, as the case may be, according to the position of the 

 sense organ on the walls of the chamber. 



Most writers on the ear have contented themselves with 

 saying that the sense organs were provided with a tectorial 

 membrane {Deckmembrajie), which frequently contained otoliths 

 as integral parts. But as the tectorial membranes can now be 

 conclusively shown to have no existence in nature as integral 

 parts of the living sense organs, it remains to be explained 

 how the otoliths are retained in place on the surface formed 

 by the tips or the sides of the hairs. 



One can hardly maintain that a mass of fine crystals of cal- 

 cium carbonate weighing from one to two ounces, lying like a 

 sediment upon the floor of the central chamber of the ear of a 

 fish of six feet length (Blue Shark, Carcharias ccerideus), can 

 really serve any physiological function auditory in nature, and I 



