34 CHIKANOSUKE OGAWA 



Protocols of experiments 



Transverse inversion. 



B II (fig. 23), F II. The endolymphatic appendage is situated 

 normally between the vest.bule and the brain. The semicircular 

 canals are not well differentiated. The macula is located ventro- 

 medially. Rotation is complete. 



D II. Differentiation of the semicircular canals is insufficient. The 

 endolyinphatic appendage is situated slightly posterior between the 

 vestibule and the brain. Rotation is complete. 



G II. The lateral and anterior semicircular canals are nearly in nor- 

 mal position. The posterior semicircular canal is not formed. The lagena 

 is visible. The endolymphatic appendage is in normal position Rota- 

 tion complete. 



G I. The endoljanphatic appendage is in normal position. No 

 differentiation of the semicircular canals has taken place. Rotation 

 is complete. 



C I. An oval sac arises from the lower part of the lateral wall of the 

 vesicle and extends dorsally. The epithelium is not as fiat as that of 

 the vesicle, but at the blind end of the sac it takes on a cuboidal form. 

 Communication with the main labyrinth takes place by a relatively 

 large opening. Hel'e the tiTie duct is absent. These two vesicles 

 are in close contact with each other. The whole structure is strongly 

 suggestive of an endolymphatic sac. The semicircular canals are 

 defective. By the position of the endolymphatic sac it can be said 

 that the labyrinth remained in its inverted position. 



C II (fig. 24). A pear-shaped endolymphatic sac buds out from the 

 lower part of the lateral wall of the labjainth and projects upward. 

 Its cavity is incompletely divided by several septa and its wall is 

 covered by cuboidal cells. A semicircular canal is found dorsally. 

 Judged by the position of the endolymphatic appendage, this labyrinth 

 must be still in its inverted position. The semicircular canal corre- 

 sponds to the lateral semicircular canal. 



E I. A vesicle is closely attached to the lateral side of the labyrinth, 

 and communicates with the latter by a small aperture. The wall is 

 composed of flat cuboidal cells. From its structure this vesicle doubt- 

 less represents an endolymphatic sac and not a semicircular canal. One 

 semicircular canal is formed dorsally, and this is probably the lateral 

 one. The labyrinth, therefore, has remained in its inverted position. 



D I. There is no evidence of an endolymphatic appendage. In 

 the medial side of the labyrinth the epithelium shows thickening. A 

 semicircular canal is formed in the upper part of the labyrinth. As no 

 endoljmiphatic appendage is visible, it is somewhat difficult to deter- 

 mine the position exactly. Generally, however, the macula occupies 

 the ventromedial part of the labyrinth, whereas here it occupies the 

 medial wall alone. This vesicle may therefore be said to have remained 

 in its transplanted position; hence the dorsally situated canal must be 

 in reality the lateral semicircular canal. 



