POSTURE OF MEMBRANOUS LABYRINTH 169 



This is the last and most imperfect labyrinth in our series. It 

 must be regarded as only a fragment. Apparently there is a 

 lagena with the characteristic finer structure, shape and position. 

 There is also a canal that corresponds in form and position to the 

 lateral canal. Otherwise the different parts cannot be very well 

 differentiated. This labyrinth is included in spite of its fragmen- 

 tary character because it shows that even such an imperfect 

 labyrinth is apparently affected in its posture by the influences 

 interacting between it and its environments. 



In a summary of the first eighteen of these experiments the 

 result that concerns us most is that in all instances where the 

 transplanted labyrinth had developed with sufficient complete- 

 ness for identification of its various parts it was found that it 

 had almost perfectly regained its normal posture. It was this 

 fact that formed the chief object of our investigation, but we 

 may add the following concerning the resultant abnormalities 

 produced by the manipulation of the vesicle at the time of the 

 operation. 



a. In 8 out of 18 experiments there developed a practically 

 normal labyrinth; 



6. Where a defect occurs following the operation it is usually 

 localized in some particular region of the labyrinth; it may be 

 confined to the anterior, posterior, or median portion, while the 

 remainder of the labyrinth is quite perfect ; 



c. The three different canals are defective with about equal 

 frequency (30 per cent), though in an individual labyrinth where 

 the canals are involved the imperfection is not distributed among 

 them equally; and the planes of the canals, whether they are 

 defective or not, are usually normal; 



d. Defects of the endolymphatic appendage occur with about 

 the same frequency as those of the canals; 



e. The lagena is imperfect more often than any other part (in 

 8 out of 18 cases) ; 



/. The acoustic nerve and ganglion were always present, though 

 in a few cases quite diminutive; the connection of the nerve with 

 the brain wall can almost always be recognized. 



