GRANULAR VENEREAL DISEASE AND ABORTION IN CATTLE. 25 
ledons of the uterus undergo corresponding development. The 
intimacy of contact between the chorionic and uterine placentas grow 
apace throughout the duration of pregnancy. Upon this fact is 
based the common observation that when abortion occurs before the 
fetus has reached or materially exceeded 12 inches in length it is 
ordinarily expelled inclosed within its membranes. This is of impor- 
tance. While retained placenta or afterbirth is notoriously common 
and serious after abortion, it is not likely to occur in early abortion, 
but only in those cases which have reached or exceeded the sixth or 
seventh month of pregnancy. The tendency to retained placenta 
increases with the advancement of pregnancy and reaches its highest 
degree in cases of premature birth, unless we except those cases which 
have reached the full period of pregnancy and given birth to living 
calves, in spite of extensive uterine infection. 
It has been supposed and taught that the firmness of union between 
the chorion and uterus decreases toward the completion of pregnancy, 
and that the parts begin to prepare before parturition for the expul- 
sion of the afterbirth. Observations on the killing floor directly 
contradict this assumption and show instead that the firmness of 
adhesion increases constantly up to birth. 
Early in pregnancy the margins of the internal os uteri are thickly 
studded over with small placentae without marked peduncles. At 
times they form a complete girdle about the internal os, and come in 
contact with each other over the os to constitute a broad, flat pla- 
cental mass 2 to 3 inches across, totally masking the os. However, 
they are not enduring, and when the fetus has reached a length of 10 
to 12 inches they begin to become detached and finally disappear. 
In the process of detachment more or less placental hemorrhage 
ensues, so that in a large proportion of cases where the fetus is 10 to 
15 inches long a careful observation of the utero-chorionic space at 
the internal os reveals a small blood clot, resting usually upon the 
uterine end of the uterine seal, where it undergoes retrogressive 
changes. At first bright red, it later becomes black, then fades slowly 
to a pale yellowish red, to constitute a sticky remnant staining the 
anterior end of the uterine seal. The amount varies; while usually 
but a drop or two, it may reach one-half ounce or more. As preg- 
nancy advances adjacent cotyledons begin to detach about their 
peripheries and small hemorrhages occur. Whether physiological or 
pathological, the hemorrhage is suggestive of importance in relation 
to contagious abortion because at the very point where the abortion 
exudate commences to form there exists generally an amount of inert 
blood coagulum to furnish a breeding ground for bacteria, like a blood 
clot in a wound. 
Another phenomenon of a somewhat similar character is common 
among the larger, more typical cotyledons. As pregnancy advances 
43378°— 14 i 
