112 Irving Hardesty 



transferred for 5 to 10 minutes to a saturated aqueous solution of 

 ammonium j^icrate. From this they were mounted in equal parts of pure 

 glycerine and ammonium picrate solution. "Wliile the methylene blue 

 brought out the structure of the membrane quite successfully at times, 

 it was found, by comparing with those pieces mounted direct in 

 glycerine, that the ammonium picrate produced in jDlaces a certain 

 amount of shrinkage and distortion. Dehydration of these pieces, how- 

 ever gradually and carefully undertaken, was found impossible from 

 the fact that in the higher grades of alcohol they invariably shrunk and 

 crumpled almost beyond recognition. In this way, especially from the 

 unstained pieces, a fair idea was obtained of the normal contour ancl 

 appearance under the compound microscope^ and measurements of 

 breadth could be made. 



Owing to lack of sufficient amniotic liquor at times when material 

 was obtained, it was found that teasing under normal salt solution gave 

 apparently as good results, and most of the best bits of fresh tectorial 

 membrane were obtained with its use. 



In no case, however careful the procedure, could a whole or even* a 

 half of the entire length of a tectorial membrane be obtained from a 

 fresh cochlea. This was due to some extent to the violent disturbance 

 necessary with the crushing and removal of the bone, but largely was 

 because of the extreme flexibility and delicacy and the remarkable 

 adhesiveness of the fresh membrane. Of the pieces obtained with por- 

 tions undistorted, many would be covered with particles of debris by 

 the time they could be mounted. Furthermore, extreme difficulty was 

 met in orienting these pieces with certainty as to their upper and under 

 surfaces. Others who have attempted examination of the membrane 

 in the fresh condition seem to have encountered similar difficulties. The 

 descriptions of Eetzius, '84, who worked in aqueous humor, of Kishi, 

 '07, who used salt solution, and of others to be referred to, show that 

 thev obtained but small pieces of the membrane, and that these were 

 imfortunately distorted. 



Therefore, the hope of obtaining an entire membrane in the fresh 

 and normal condition had to be abandoned, and experiments were begun 

 for a fixing fluid whose action would result in the least possible distor- 

 tion of this evidently peculiar structure. This fluid should preferably 

 be a decalcifying fluid as well. It was already apparent that the fluid 

 could not contain alcohol unless accompanied by some ingredient which 

 would counteract its shrinkage effect. Van Gehuchten's (Carnoy's) 



