264 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, 
