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G. CARL HTJBER 



in figure 15, two views of each model being shown. Five of 

 the models, A to E, show 8-cell stages. In F, there is figured 

 an 11-cell stage, three of the cells having completed the next 

 following division. As may be seen from the figures, the form 

 of these morula masses is not spherical but in the main slightly 

 oval, with further irregularities better shown in the models than 

 in the illustrations, due to the fact that the egg masses con- 

 form to the shape of the lumen of the oviduct in the region in 

 which they are found. The mucosa lining the segment of this 



Fig. 15 Models, obtained by reconstruction after the Born method, of 8- 

 cell and 11-cell stages of the albino rat. Rat No. 57, 3 days, 17 hours. X 200. 

 Two views of each model is presented. A-A', to E, E' are of models of 8-cell 

 stages; F and F' of a model of a 11-cell stage. 



oviduct containing the ova presents four quite regular longitudi- 

 nal folds. In figure 16, there is presented a model of a detailed 

 reconstruction of the segment of the oviduct containing the ova, 

 their relative position in the tube and their relation to the major 

 folds is clearly shown. One of these folds it was necessary to 

 in part remove so as to bring to view in the drawing certain of 

 the ova. In figure 17, there is reproduced a portion of one of 

 the sections of the series from which the model shown in figure 

 16 was made. The fold of the mucosa occupying the center 



