OHAPTEE XXI. 



Abortion Extraordinary in Milk Cows, 

 From Artery Engorgement and Embryo Starvation. 



That there is an antecedent increase of blood in the 

 udder-supply arteries, corresponding to any increase that 

 is made in yield, is equally necessary and certain. And 

 that such increase in blood, when large and rapidly made, 

 engorges these arteries is very evident. Several import- 

 ant, but z^«natural, changes in the udder-supply arteries 

 result from their engorgement : — 



First, excessive and excessively rapid expansion of the 

 arteries that supply the milk-glands with blood, results 

 from equally excessive and rapid increase in the bulk of 

 blood, and the quantity of food it is formed from ; the 

 evident proofs of this being found in the udder and the 

 milk pail. 



As is well known, the milk-yield of cows, particularly 

 in those supplying cheese factories with milk, is, in num- 

 bers of instances, doubled in less than three months of 

 time; in some instances 70 to 100 per cent increase in 

 yield being made in six to eight weeks. In instances 

 where so large an increase is made in three months, this 

 increase in yield is at the rate of 140 to 200 per cent or 

 more in six months, which is a short milking season, there 

 being a corresponding increase in the size of the udder 

 and its supplying arteries at the same time. This increase 

 of blood in the mammary arteries supplying the udder is 

 so large that, if continued, it would enlarge the tubular 



