ON PUERPERAL FEVER IN THE COW. 
493 
earlier months of uterine gestation. A cow may, by preserving 
the former of these conditions, continue to yield milk during seve- 
ral years; but, during the latter months of gestation, its secretion 
sensibly diminishes, and, for some weeks previous to parturition, 
it is ordinarily entirely suspended. We all know that a large 
supply of milk and an advanced state of gestation are incompatible. 
With reference to the relation existing between the quantity of 
milk yielded and the period of gestation, it may be stated that, in 
an average number of cases, before the fifth month of conception, 
a diminution of one-third of its quantity has taken place — by the 
sixth month, two-thirds — and, soon after the seventh it is usually 
entirely suspended. In what other way can we account for this 
than by supposing that the foetus exercises, for its development, 
a demand upon the organic functions equivalent to the quantity of 
milk that would otherwise have been yielded ; requiring, as it does 
in common with that secretion, a large quantity of circulating fluid 
for its formation. 
Fully to provide for the foetal growth, there is, in mammalia 
during gestation, a greatly increased, and, the nearer parturition, a 
more rapidly increasing development of the vascular system in the 
parent ; but, perhaps, in no animal does this correspond in extent 
with that of the cow, which may be accounted for by the fact that 
Providence has destined her, not only amply to provide support 
for her offspring, but also to contribute largely towards that of 
mankind. Hence her peculiar liability to various diseases, both 
in a puerperal and barren state, arising from the existence of a 
larger quantity of blood in the system than is immediately neces- 
sary for growth and nutrition. 
In making these remarks my intention is to render it obvious 
that, shortly previous to, and at the time of, parturition, there is, 
from the requirement of increased activity both in the animal and 
its organic functions, an increased stimulus or action required to be 
exercised by the nervous centres in order effectually to secure 
their performance. 
It has been ascertained by Dr. R. Lee of London, that, during 
conception, not nerves only, but considerable ganglia, previously 
not perceived to exist, are apparent in the vicinity of the uterus. 
Such stimuli, of a nature and duration unknown on any other 
occasion, must, therefore, be favourable to a development of dis- 
ease, by rendering the nervous system susceptible of impressions 
which, under other circumstances, might not have operated thereon. 
This extremely vascular state of system is, in ordinary cases, 
relieved by a plentiful secretion of milk, which nature, as it were, 
providing against consequences, excites the udder to secrete some 
time prior to parturition. In other cases it is different ; and we 
VOL. XVII. 3 T 
