POSTURE OF MEMBRANOUS LABYRINTH 155 



will not be reported on in this paper; we limit ourselves to the 

 question of whether environmental control does or does not exist. 

 It may be pointed out that the above operative procedure offers 

 a complete and severe test for the existence of such control. It 

 is so arranged that we have for the experiment a transplanted 

 foreign ear vesicle, which does not naturally fit in its new pocket 

 and which is intentionally placed in a posture as abnormal as 

 possible. 



RESULTS OF THE EXPERIMENTS 



At the outset it may be stated that in all cases where the laby- 

 rinth had developed into a structure with sufficient completeness 

 for the identification of its relations, it was found that the position 

 of its canals and various chambers as regards the surrounding 

 structures was practically normal, in spite of the manipulation 

 it had undergone at the time of the operation. As has previously 

 been shown (Streeter '07, p. 433) the posture of the labyrinth can 

 be determined both by the histological structure of its walls and 

 by its outer form, as determined by wax-plate reproductions. 

 The description of these morphological characteristics will not 

 be repeated here; it will be sufficient to state that they are so 

 definite that the various parts of the labyrinth can be recognized 

 without difficulty, even though they happen to be incomplete or 

 unequally developed. 



For the sake of compactness table 1 is annexed in which are 

 detailed the separate features of each of the nineteen transplanted 

 labyrinths as found on examination. Each feature is marked 

 'normal', 'imperfect,' or 'absent,' indicated by the signs A^, / 

 and 0. These are used in a liberal sense so, that 'normal' signi- 

 fies practically normal, and includes structures abnormally large 

 or small; 'imperfect' signifies quite abnormal, the characteris- 

 tics, however, being sufficiently well defined for identification of 

 the structure; and 'absent' means either completely absent or 

 unrecognizable. 



The features as listed will for the most part explain themselves. 

 It may be mentioned, however, that by canal planes is meant the 

 relative position of the canals as regards each other. Planes 



