Wilson, Membrana Tympani. 461 



plexuses and by independent fibers which pass from one to the 

 other. 



Deinike ('05) in his paper on the nerves of the membrana tym- 

 pani of the horse and ox also refers to the difficulty of the technique 

 " So viel ich mich auch bemiihte, eine tadellose Farbung des nerven 

 an Trommelfellen von Tieren mittlerer Grosse wie Hund, Katze 

 u. a. zu erzielen, stets bleiben meine Versuche resultatlos" (p. 117). 

 He describes the nerves as coming from the n. auriculo-temporalis 

 and from the n. tympanicus. His account agrees in the main 

 with that of Jacques and Calamida, but in addition he figures 

 endings between the radiating and circular tissue and at the lim- 

 bus; the former are plate-like bodies which probably act "Zur 

 Bestimmung des Spannungsgrades des Trommelfells;" the latter 

 correspond to endings in tendons elsewhere. 



I have examined the membrana tympani of the dog, cat, rabbit, 

 and monkey (Macacus rhesus), as well as several obtained from 

 man. In the main they agree; points of variation will be pointed 

 out later. The results, so far as man is concerned, are not com- 

 plete and will be published later. 



Those who have worked on the nerves of the membrana tym- 

 pani will agree with Jacques and Deinike that there are few 

 parts of the body where one has so many difficulties to overcome 

 and so many disappointments to encounter. Osmic acid is vir- 

 tually useless, partly because so many of the nerves are nonmedul- 

 lated and partly because of the abundance of fat-containing bodies 

 lying on the cuticular part, which stain with osmic acid. Chloride 

 of gold and Golgi have in my hands proved very unsatisfactory. 

 In my opinion the intravitam methylene blue method gives the 

 best results, especially if the injection be made into an artery and 

 fixed in ammonium molybdate. The method of Dogiel is less 

 satisfactory. In the human tissue where the ear cannot be pro- 

 cured immediately on death I have obtained results six or eight 

 hours postmortem, by the following method : I immerse the drum 

 in a mixture of methylene blue and weak osmic acid solution for 

 two to four hours; it is then directly transferred to the ammonium 

 molybdate solution. By this method the myelinated nerves are 

 seen as dark brown fibers with a blue axis cylinder, and the non- 

 myehnated nerves blue; the rest of the membrane is light brown. 

 While this method is not always successful it at times gives sur- 

 prising results. 



