650 PATHOLOGY OF PARTURITION. 



dilatation of the posterior aorta, and slowing of the circulation. The 

 primary cause of all this is bad management of the Cows, and pressure 

 of the foetus on the stomach and intestines, diaphragm, vena cava, and 

 posterior aorta. 



3. Derangement or Paralysis op the Nerve-Centres. — Many- 

 high authorities — among them Kohne, Binz, Carsten-Harms, Wan- 

 novius, Busch, Bull, Bychner, Baumeister-Bueff, Barlow, and others — 

 have maintained that the disease is primarily a derangement or 

 paralysis of the ganglionic nervous system, which affects, or is extended 

 to, the spinal cord and brain during the course of the disease. The 

 following explanation is offered in support of this opinion. A too easy 

 birth throws out of play a certain amount of the nervous force destined 

 to the accomplishment of this act. Hence, there is a disproportion 

 between the polar tension of the force conveyed by these nerves and 

 the muscular irritability, and consequently an obstacle to the conducti- 

 bility of the nerves charged with the distribution of this superfluous 

 portion of the nerve force. Barlow thought that this disturbance in 

 the function of the sympathetic nerves produces arrest of secretion and 

 general congestion, especially of the brain and spinal cord. Contamine 

 is more or less a partisan of this theory, as he explains the origin of the 

 disease by stating that a reserve of nervous influence which is not 

 expended in the animals that calve easily, by a reflex movement acts at 

 first upon the spinal cord, and afterwards on the brain. 



4. Alterations in the Constituents of the BLooD.^The opinion 

 has been emitted that the collapse is due to an undue preponderance 

 of water in the blood of some Cows, during the later stages of pregnancy, 

 and that this results in cerebral oedema after parturition. Another 

 opinion is that the collapse is a kind of leucocytha^mia, from the increase 

 of white corpuscles in the blood during pregnancy, and after par- 

 turition. 



But neither of these opinions can be reconciled with the symptoms 

 or post mortevi features of the malady. 



A third opinion attributes the disease to an excess in the proportion 

 of red corpuscles, and this certainly is more acceptable than those just 

 noticed. 



5. The Presence of something Abnormal in the Blood, which 



LEADS TO THE DEVELOPMENT OF THE SyMPTOMS AND LeSIONS OBSERVED. 



— It has long been a popular notion in several countries that puerperal 

 apoplexy is caused by the absorption of the milk into the blood circula- 

 tion ; hence the designation of "milk-fever" given to the disease in 

 England, France, Germany, etc. Lafosse's theory had something of 

 this notion in it. According to him, the malady is due to the circum- 

 stance that the milky fluid secreted by the cotyledons, and absorbed by 

 the chorial villi for the nutrition of the foetus, being no longer separated 

 from the blood after parturition, remains in the circulation and accumu- 

 lates there until the mammary glands eliminate it. When these glands 

 act promptly, the fever is imperceptible or almost nil ; but if they are 

 slow in secreting, then arises a more or less intense morbid disturbance, 

 due more especially to the presence in the blood of a product foreign to 

 its normal composition. Without commenting at any length on this 

 theory, it may be sufficient to mention that in some cases of parturient 

 apoplexy the function of the mammary glands is not suspended; though 



