220 Oattle Problems. 



ively closed. The artery,/", being relaxed, the quantity of 

 blood it conveys to the udder, /, cannot be reduced, conse- 

 quently the supply of blood to the embryo. A, cannot be 

 increased. Relaxation of the artery, /, prevents its con- 

 traction to the dotted lines, o/ hence the embryo supply, ,(,>■, 

 cannot be increased to g2, as is required, to continue its 

 growth to mm. Consequently the embryo-growth is ar- 

 rested at M, and the embryo is starved to death, and 

 aborted at the half-size, H', instead of being enlarged by 

 growth to the full-term size, turn, as is required for full-term 

 delivery. The detached figs. 2 and 3, same plate, indi- 

 cate, by the reversed angles, that to continue embryo 

 growth to the full term, mm, the blood supply to the udder, 

 /, must be reduced as much as the blood supply of the em- 

 bryo, k, is increased, to continue embryo breeding. Fig. 4 

 shows a greatly-enlarged and relaxed artery, the walls be- 

 ing much thinned down by an engorging and relaxing in- 

 crease of blood, as appears in the sections, d and l>2. The 

 relaxed and enlarged portions of the artery wall, or tissue, 

 c and 1:2, show the spreading of the artery fibres further 

 apart, very much weakening the walls, as takes place when 

 the arteries are expanded to nearly twice their natural size, 

 by an engorging and relaxing increase of blood, and its 

 expansive pressure against the artery walls. 



