32 CHIKANOSUKE OGAWA 



Transplantation from Rami to Amblystotna. A I. Just at the medio- 

 dorsal part of the anterior semicircular canal, and separated from it 

 by a thin septum, there is a small vesicle composed of cuboidal cells, 

 while the canal is lined, as usual, by a layer of flat cells. Judged by 

 the nature of the cells and the location of this structure, it must represent 

 a nidimentary endolymphatic sac. The other semicircular canals and 

 the labyrinth are in normal position. 



B II (fig. 22), C I. No endolymphatic appendages can be seen in 

 their usual position. The semicircular canals are almost normal in 

 form. Position normal. 



A II. Vesicle shows no differentiation. It is too abnormal to deter- 

 mine its position. 



A IV. The structure is too abnormal to admit of any definite 

 conclusion. 



B I, C II. No vesicle could be found. 



INVERSION OF THE EAR VESICLE ON ITS TRANSVERSE AXIS 



As already mentioned, Spemann in his experiments on inversion 

 obtained a different result from those of Streeter. He inverted 

 the ear vesicles of Rana esciilenta about their transverse axes — 

 that is, upside down — and after the operation kept a cover-glass 

 on the wound for half to three-quarters of an hour to prevent the 

 vesicles from slipping back. Out of twelve specimens operated 

 upon he found that the vesicle remained in its inverted position 

 in nine cases. In two only a 'Bruchteil der Anlage' w^as rotated, 

 and in one case restoration of the original position was observed. 



Concerning this discrepancy from Streeter 's results, the latter 

 gave the following explanation: ''Spemann raised a relatively 

 large square flap of skin and exposed a larger area of the deeper 

 structures, perhaps thereby injuring the environment in a way that 

 lessens the postural interaction between it and the ear vesicle. 

 In the second place the use of the w^eight may retard the move- 

 ment of the vesicle and prevent its rotation." 



This naturally raises the question, What would be the result 

 if inversion on the transverse axis were carried out by the method 

 used by Streeter? To throw light upon this problem has been 

 the purpose of the present study. 



I operated upon seventeen animals in the manner already de- 

 scribed, keeping the w^ound free from any weight after the opera- 



