Characteristics of Abortion. 225 



No other known cause than prevented increase in blood 

 supply to the embryos, accounts for the sudden arrest of 

 their growth by the stoppage of the placental circula- 

 tion, and the consequent death of the embryos ; nor for 

 the evidences of the embryos being starved ; nor for the 

 clusters of abortions that occur together ; nor for the greater 

 liability of " new " cows and heifers to abort ; nor for the 

 greater liability of cows to second, than to first abortions. 

 But the certain engorgement of the udder-supply arteries 

 from over-strain, which is as certain as the increase of 

 blood, itself, by over degrees of rapid engorgement with 

 blood, accounts for, and explains all these extraordinary 

 and peculiar characteristics as the necessary result of over- 

 rapid increase, in feed, blood, and artery expansion, in de- 

 grees that lead to the /oss of contractile power in the udder- 

 supply arteries, thus preventing increase of embryo nutri- 

 tion, and causing embryo death, and so making abortment 

 a necessitv. 



