20 



G. CARL HUBER 



this stage, free in the lumen, is well shown in figure 5, which is 

 from a longitudinal section of a loop from the left oviduct of 

 rat No. 109, showing three ova, with but few remaining discus 

 cells and a thread of coagulum linking the ova together, an 

 appearance quite characteristic at this stage. The figure was 

 drawn by aid of camera lucida from a single section. All of the 

 ova, of which there are seven, distributed through this loop, con- 

 tain two pronuclei; in none of the ova figured do the two pronuclei 



Fig. 5 Camera lucida drawing of a portion of a section of the left oviduct of 

 rat No. 104, 24 hours, 15 min. X 100. Three ova with a few discus cells, are 

 shown as lying free within the lumen. The ova are in the pronuclear stage, not 

 shown in this section, but readily ascertained by tracing through the series. 

 The loop of the oviduct here shown in section is cut longitudinally, thus the 

 folds of the mucosa are not prominent. 



fall in the same section. My series contains seven oviducts with 

 pronuclear stages, with accompanying ovary, cut serially. Only 

 one of the oviducts, rat No. 106, was reconstructed in wax. In 

 the other six, graphic reconstructions were made. This permits 

 analysing the loops, determines their sequence, but does not 

 readily admit of measuring their length. In the six oviducts 

 graphically reconstructed, the position of the ova, the number 

 of which varies from one to seven in the several tubes, is essen- 

 tially as in the wax reconstruction figured. It would appear, 



