86 AVERS. [Vol. VI. 



Max Schultze (1858, 256) discovered the auditory hairs of the 

 cristas acusticae of the fish ear (Teleost). He found tliem pro- 

 jecting freely into the endolymph. 



Franz Eilhard Schulze (1862, 255) re-examined the question, 

 and found that Schultze's observations were correct so far as 

 they went ; but he discovered tliat the hairs were mucli longer 

 than Schultze had described them to be. They were equal in 

 length to at least one-half the diameter of the ampullae, and 

 probably were even considerably longer. 



Lang (1863, 175) found in preparations of the ampullae treated 

 with hydrochloric acid and alcohol that a finely striated mass, 

 which he called the " cupula terminalis," covered the auditory 

 crest. He considered the auditory hairs, previously described 

 by Schulze and others, to be artifacts resulting from the trans- 

 forming action of the acid and alcohol on the cupula. 



Hensen (1863, 130) confirmed the discoveries of Schulze, and 

 Hasse (1870, 1 16) accepted the arguments of Lang, but regarded 

 the hairs as relatively short structures. 



Retzius (1872, 238) agreed with Lang and Hasse. 



Paul Meyer {1876, 192) was in essential agreement with Hasse 

 and Retzius. 



Dr. Kuhn (1877, 170) found in the ampullae of all the species 

 he worked upon (fishes, amphibia, and reptiles) what he consid- 

 ered to be a cuticular structure of such form and extent as to 

 serve as a dome-shaped cover of the crista and its sensory hairs, 

 effectually shutting off the hair chamber from the rest of the 

 ampulla. This organ — the so-called cupula terminalis — was 

 of form and structure varying with the species studied. 



Kuhn says {loc. cit. p. 316) : "An frischen Praparaten ist es 

 unmoglich dieselbe in situ zu Beobachten ; sie fallt von der 

 crista ab und wird ihrer Durchsichtigkeit halber stets iiber- 

 sehen." In ears hardened in chromic or osmic acid, Kuhn 

 was able to study the structure and relations of the body to the 

 hair cells and to the crest. Even in these cases, however, the 

 cupulae were frequently absent wholly or in part. The base of 

 the cupula was always found to be concave, repeating, as a rule, 

 the curve of the crista acustica. He never found the ciipiila 

 projecting beyond the edges of the hair-cell territory ; and conse- 

 quently any relation to the planum semilunatum was not to be 

 thought of. The body of the cupula, rising from its concave 



