ANATOMICAL AM) PHYSIOLOGICAL STUDIES ON 



Kolliker ('67) finds the membrane 45 [x thick in the ox. In 

 the guinea-pig it is 15 [x in the thickest place, according to 

 Schwalbe s 7 . Middendorp ('67) gets in mammals generally 

 a very thin membrane, about 1 a thick. Retzius ('84) states 

 that in the thickest part in the rabbit it measures 27 [x, in the 

 < at 32 t<> 50 x, and in man 24 to 25 fx. Hardesty finds in the 

 young pig an average thickness of the teased membrane of 

 7)0 j. and in an adult hog 119.3 ;x. I get 35 [x as an average in 

 the adult albino rat after twenty days of age, varying from 32 

 to 38 (x. My result is therefore closest to that for the cat as 

 obtained by Retzius. These results are plainly influenced by 

 tin- dissimilar technical methods used by the several investigators. 



About the outermost end of the membrane there are still two 

 different views. One view is that the outer end of the membrane 

 projects beyond Hensen's prominence; Kolmer ('07; pig, calf 

 goal and horse); Hardesty ('15; pig, hog) Shambaugh ('10; pig). 

 Others assert that the membrane terminates with its outer edge 

 at the outer boundary of the outermost series of the outer hair 

 cells. My preparations show that in the rat the outer end of 

 the membrane does not reach Hensen's prominence. 



Possibly this difference is due to the technique of preparation. 

 In the figures drawn by many authors we can recognize many 

 artifact- and postmortem changes in the cochlea. Even in the 

 figures of Kolmer ('07) we see these changes, although he injected 

 the tixin-i solution through the carotid artery. Held ('09) says 

 in hi- criticism of Hardesty 's figures that "figures 6 and 7 wie 

 Bchon Hardesty selbst vermutet hat, sicherlich auf einer Ver- 

 quellung beruhen " 



I myself never observed such a gigantic membrane as Hardesty 



15), Shambaugh ('10), and others show in the cochlea 



of the pig. On the other hand, I cannot absolutely deny that 



there may have been shrinkage in the cochleas prepared by my 



methods, though I see no evidence of it. 



"in- present knowledge, however, the method of vital 



3 considered the best available, as already maintained by 



Siebenmann and Yoshii ('08), Metzner and Yoshii ('09), Nager 



11,1,1 Yoshii 10 . Wittmaack and Laurowitsch ('12), and others. 





