258 G. CARL HUBER 
TABLE 1 
ee es ee — aeea Cae 2 eee 
| STAGE OF DEVELOPMENT 
RECORD HOURS AFTER BEGINNING | NUMBER OF | a 
NUMBER OF INSEMINATION OVA Predcleas | Second matu- 
ration spindle 
106 24 hours 8 8 
107 24 hours 11 10 1 
108 24 hours i i 
109 24 hours, 15 min. 9 8 1 
110 24 hours, 15 min. 8 8 
Total 43 34 9 
Ovulation may have occurred so late that the spermatozoa 
may have died before the ova reached the ampullar portion of 
the oviduct. This explanation, it would seem, is invalidated 
by the fact that the position of the ova in the oviduct, as shown 
by graphic reconstruction, is essentially the same as in the other 
four rats studied, and in which fertilized ova were found, so that 
ovulation must have preceded the killing of the animal by some 
hours. The other reason, more plausible, attributes non-fertili- 
zation to a pathologie condition of the genital tract. In this rat, 
one ovary was distinctly pathologic, with periovarian capsule 
greatly distended with a sanguinous lhquid, while the upper end 
of the uterine horn with adjacent oviduct on the other side, 
as seen in sections, presented evidence of inflammation and epithe- 
lial desquamation, in part occluding the lumen. It seemed 
evident, therefore, that the spermatozoa introduced in the genital 
tract were unable to penetrate to the oviduct and consummate 
fertilization. The other two unfertilized ova, found with ova 
in the pronuclear stage, were in oviducts in which no spermato- 
zoa were found. Both in the mouse and the rat, relatively few 
spermatozoa reach the upper end of the oviduct; too few, it would 
seem, to consummate fertilization of all the ova in certain cases. 
In all of the ova which contained the second maturation spindle, 
this was in the monaster phase and in tangential position. In 
size, shape, and chromatin configuration, all presented the char- 
acteristics described and figured by Sobotta and Bureckhard and 
Kirkham and Burr, therefore, need not be considered further. 
