GROWTH OF THE INNER EAR OF ALBINO RAT 69 



His idea was strongly opposed by Bottcher ('72) and my results 

 are also opposed to Gottstein's view. 



8. The radial distance between the labium vestibulare and the 

 habenula perforata. The purpose of this measurement is to 

 determine how the habenula perforata stands in relation to its 

 surroundings during the development of the cochlea. The meas- 

 urements of this distance is difficult. During the earlier stages, 

 the labium vestibulare is quite undeveloped, especially in the 

 upper turns. At birth we see on the inner surface of the greater 

 epithelial ridge a small prominence under which the epithelial 

 cells are short and pressed together so that the nuclei seem to be 

 arranged in several rows (fig. 4). This appearance is due to the 

 invasion of the subjacent connective tissue into the epithelium. 



Thus the vestibular lip arises. We do not see a furrow at this 

 time and cannot use the top of the furrow as a point for measuring 

 as did Hensen ('63) in the ox and Bottcher ('69); in the em- 

 bryo cat). To the measure the distance between the insertion of 

 Reissner's membrane and the habenula perforata has no meaning 

 for my purpose, because the length of the limbus laminae spiralis 

 changes with age. 



Thus I have measured the distance between the small epithelial 

 prominence on the axial side of the greater ridge, corresponding 

 to the edge of the labium vestibulare, and the habenula perforata. 



In table 41 (charts 17 and 18) are given the values of the radial 

 distance between the labium vestibulare and the habenula 

 perforata. At the foot of the last column are given the ratios 

 from 1 to 546, 9 to 546, and 20 to 546 days. As we see, the 

 values are a little bit smaller at the earlier stage. After nine 

 days they are almost the same in every stage. The small differ- 

 ences at the earlier and later stages are probably due to the 

 retarded development of the labium vestibulare. 



When we consider the values for this distance in each turn, 

 it is evident that these increase from base to apex. In the con- 

 densed table 42 this relation is shown. 



Hensen ( '63) finds that the distance from the top of the furrow 

 to the habenula perforata is in the fetal calf and in the ox the 



