ON THE MEMBRANA BASILARIS, THE MEM- 



BRANA TECTORIA, AND THE NERVE 



ENDINGS IN THE HUMAN EAR.' 



HOWARD AYERS, 



PROFESSOR OF HISTOLOGY IN THE MEDICAL DEPARTMENT OF THE UNIVERSITY 



OF MISSOURI. 



THE materials for this investigation consisted of the ears of 

 three human embryos and two adult males. The embryos 

 were two and a half, three and a quarter, and four months old 

 respectively, and since the ear capsules of these five subjects 

 were obtained in a practically living condition, it was possible 

 to use with good success both the Golgi and the methylene-blue 

 staining methods in studying them. Both of the adults fur- 

 nished ears that were normal beyond a doubt ; they came from 

 an electrocuted murderer, on the one hand, and a robber shot 

 inflagrante delicto and instantly killed, on the other hand. In 

 the one case the ears were removed at once and preserved in 

 an aqueous solution of corrosive sublimate, while in the other 

 they were studied in their fresh condition. Of the embryonic 

 ears, one was studied in the fresh condition, one was used for 

 serial sections, while the third was used for the dissection of 

 the membranous ear. 



This exceptionally favorable adult material has given excel- 

 lent results, and we may rest assured that the histology is per- 

 fectly normal and unaffected by sickness or organic disease, 

 and, since I have used every care to preserve the living condi- 

 tions in my preparations, and, by previous study of the living 

 cochlea of mammals other than man, thoroughly prepared my- 

 self to detect alterations due to reagents, I can assure you that 

 all of the histological characters with which we have to deal 

 have been fixed in death as they were in life. In 1892, after 

 several years spent in the investigation of this subject, I pub- 



1 Read at the meeting of the Association of American Anatomists, held at 

 Ithaca, N. Y., Dec. 28-30, 1897. 



