DEVELOPMENT OF THE ALBINO RAT 269 
applied to the outside of the ovarian capsule, and conspicuous 
in all of the figures of models of the oviducts here presented. The 
detail of the distribution of the ova in the tube is given in figure 
8, a reconstruction under a higher magnification of the segment 
of the oviduct containing the ova. The lumen is exposed so 
that the character of the mucosal folds may be seen. The ova 
are spaced in a segment of the tube measuring 3 mm., and are 
Fig. 8 Model of the segment of the right oviduct of rat No. 59, 2 days, con- 
taining the four 2-cell stages as shown in figure 7.  X 50. Note the absence of 
prominent folds in the mucosa. The segment presented in the reconstruction 
measures 3 mm. The four 2-cell stages contained in this tube are relatively 
widely spaced. 
in this case more widely separated than is usual for this stage. 
In figure 9, there is reproduced a reconstruction of the left ovi- 
duct of rat No. 62, killed 2 days, 22 hours after the beginning 
of insemination. This tube was also cut a little before its in- 
sertion into the uterine horn. The portion reconstructed meas- 
ures 2.45 cm. In it there are found five ova in the 2-cell stage, 
situated about 2 em. from the fimbriated end, and in the last 
loop of the third segment of the oviduct. The five ova are closely 
