NINTH ANNUAL YEAR BOOK— PART X 457 
many old dairy farms, from which the mineral matters of the surface 
soil have been sold off in the milk or cheese for generations and no return 
has been made in food or manure purchased. Here is the craving of an 
imperative need, and if it is not supplied the health of the cow suffers 
and the life of the fetus may be sacrificed. 
Among other causes of abortion must be named the death or the 
various illnesses of the fetus, which are about as numerous as those of 
the adult; the slipping of a young fetus through a loop in the naval 
string so as to tie a knot which will tighten later and interrupt the flow 
of blood with fatal effect, and the twisting of the naval string by the 
turning of the fetus until little or no blood can flow through the con- 
torted cord. There is in addition a series of diseases of the mucous mem- 
brane of the womb, and of the fetal membrane (inflammation, effusion of 
blood, detachment of the membranes from the womb, fatty or other de- 
generations, etc.), which interfere with the supply of blood to the fetus 
or change its quality so that death is the natural result, followed by 
abortion. 
CAUSE OF CONTAGIOUS ABORTION. 
While any one of the above conditions may occur with the contagious 
principle in precipitating an epizootic of abortion, yet it is only by 
reason of the contagium that the disease can be indefinitely perpetuated- 
and transferred from herd to herd. When an aboring cow is placed in a 
herd that has hitherto been healthy, and shortly afterwards miscarriage 
becomes prevalent in that herd and continues year after year, in spite 
of the fact that all the other conditions of life in that herd remain the 
same as before, it is manifest that the result is due to contagion. When 
a bull, living in a healthy herd, has been allowed to serve an aborting 
cow, or a cow from an aborting herd, and when the members of his own 
herd subsequently served by him abort in considerable numbers, contagion 
may be safely inferred. Mere living in the same pasture or building does 
not convey the infection. Cows brought into aborting herd in advanced 
pregnancy carry their calves to the full time. But cows served by the in- 
fected bull, or that have had the infection conveyed by the tongue or tail 
of other animals, or by their own, or that have had the external genitals 
brought in contact with wall, fence, rubbing post, litter, or floor previ- 
ously soiled by the infected animals, will be liable to suffer. The Scot- 
tish abortion committee found that when healthy, pregnant cows merely 
stood with or near aborting cows they escaped, but when a piece of cotton 
wool lodged for twenty minutes in the vagina of the aborting cow v/as 
afterwards inserted into the vagina of a healthy, pregnant cow or sheep, 
these latter invariably aborted within a month. So Roloff relates that in 
two large stables at Erfurt, without any direct inter-communication, but 
filled with cov/s fed and managed in precisely the same way, abortion 
prevailed for years in the one, while not a single case occurred in the 
other. Galtier finds that the virus from the aborting cow causes abor- 
tions in the sow, ewe, goat, rabbit, and guinea pig, and that if it has been 
intensified by passing through either of the two last-named animals it 
will affect also the mare, bitch, and cat. 
