228 Cattle Froblems. 



10. The laws of embryo life require a constant in- 

 crease in growth and size, and a corresponding increase 

 of nutriment to add to and enlarge size, so increasing 

 embryo growth — which is always enlargement by assimila- 

 tion of an increased blood supply to the embryo. 



11. The mammary blood is naturally provided and 

 circulated to form and increase embryo growth, the two 

 sets of mammary arteries being located and adapted to 

 one succeed the other in use, the uterine set supplying the 

 embryo previous to birth ; and the udder-supply set sup- 

 plying the milk-glands for the calf, after its full-time de- 

 livery. 



12. The division of the mammary blood to supply 

 both the embryo and the milk-glands at once does not in- 

 crease its total quantity, so the embryo nourishment must 

 be deficient whenever the supply is too small to enlarge 

 embryo size or growth. Hence, groiuth by increased nu- 

 trition must cease, unless the placental circulation be in- 

 creased according to increasing size and demand of the 

 embryo. 



13. But the supply of blood to the embryo cannot be 

 increased, the only source of increase being the udder- 

 supply, which cdLwnot be reduced, as the engorged size of 

 the udder-supply arteries remains fixed and ?^«diminished, 

 by reason of continued distention and relaxation. In this 

 way the effect of the udder-supply artery engorgement is 

 embryo starvation. And abortment follows as the neces- 

 sary alternative, to prevent the death of the cows. 



14. Nearly all the aborted embryos are dead previous 

 to delivery ; their appearance, and that of the aborting 

 cows, showing no marks of disease, but clear evidences of 

 embryo starvation, both in the drained vessels of the 

 placenta, and the emaciated or starved appearance of the 

 embryos when delivered. 



15. It is daily twice demonstrated in the pail, and 



