878 SCOTTISH METROPOLITAN VETERINARY ASSOCIATION. 
the ganglia of the sympathetic, would produce the same result as 
division. 
Sudden excitation of the abdominal sympathetic often dimi¬ 
nishes the action of the heart by reflex action, and sometimes 
kills the excitation passing to the cord, thence to the origin of the 
tenth-nerve, thence to the heart (Brown-Sequard). That the 
sympathetic system is the first to become affected is proved 
by the arrestation of the lacteal secretion (in post-partum 
cases the secretion of milk is noticed to stay suddenly a few 
hours preceding the attack, thus causing, as I have before stated, 
a revulsion of blood to the system which would have been used 
in lactation, and this is aggravated by the continuance of feeding 
and the want of exercise) and the early appearance of constipa¬ 
tion. This loss of function is followed, first, by loss of power 
in the secretory and excretory organs, and accumulation of dele¬ 
terious matter in the system ; secondly, by loss of power in the 
arteries and capillaries; thirdly, by interference with respiration. 
The consequence of the paralysis of the arteries is the accumula¬ 
tion of blood in the capillaries of the lumbar portion of the spinal 
cord— i. e. when the pressure has been on the hypogastric or 
lumbar plexus, on the transverse inter-communicating branches 
which have to cross the posterior aorta, or upon the sacral branch; 
and, in a certain degree, when the result of reflex irritation; 
giving rise to paralysis or loss of power in the hind limbs, these 
being always the first to become affected—analogically, strong 
confirmation of this view is afforded by the post-partum spinal 
and cerebral pains of women commencing in that region and 
gradually extending to the head, becoming diffused thence over 
the front and sides of it in the direction of the various nerves — 
gradually the congestion extends along the cord to the cere¬ 
bellum, co-ordination of movement is lost, and paralysis of the 
fore extremities ensues; the cerebrum also participating, the senses 
become paralysed; in some instances all this is the work of a 
few seconds; finally, the medulla oblongata is involved (either 
from counter-pressure or from its intimate connection with the 
pneumogastric and sympathetic nerves) giving rise to arrestation 
of the respiratory process. The continuance of the act of breath¬ 
ing may be thought to contradict this, such, however, is not 
the case, for if the pneumogastric nerves are divided or paralysed, 
respiration will be carried on, though more slowly, by the 
phrenic nerve, and the intercostal and other muscles; and, it is 
probable, says Brown-Sequard, “ that the impression may be con¬ 
veyed to the medulla oblongata through the sensitive nerves of 
all parts in which the imperfectly aerated blood flows; yet, the 
respiration being restored, adds to the otherwise injurious effects 
of division of the nerves/'’ 
