DISEASES OF THE GENERATIVE ORGANS. 181 



form gives place to a more or less irregular nodular mass, while later 

 still the head, limbs, and body of the fetus may be distinctly made out. 

 The chief source of fallacy is found in the very pendant abdomen of 

 certain cows, into which in advanced gestation the fetus has dropped 

 so low that it can not be felt by the hand in the rectum. The absence 

 of the distinct outline of the vacant womb, however, and the clear indi- 

 cations obtained on external examination through the right flank will 

 serve to prevent any mistake. The fetus may still be felt through the 

 rectum if the abdomen is raised by a sheet passed from side to side 

 beneath it. 



Still another sign is the beating of the fetal heart, which may be 

 heard in the latter half of pregnancy when the ear is pressed on the 

 think in front of the right stifle, or from that downward to the udder. 

 The beats, which are best heard in the absence of rumbling, are about 

 120 per minute, and easily distinguished from any bowel sounds by 

 their perfect regularity. 



DURATION OF PREGNANCY. 



From extended statistics it is found that the average duration of 

 pregnancy in the cow is 285 days. A calf born at the two hundred and 

 fortieth day may live, and a case is reported by Dietrichs of a calf born 

 on the three hundred and thirty-fifth day, and another by the American 

 Journal of Medical Science as born on the three hundred and thirty- 

 sixth day. It is the general observation that in the majority of pro- 

 longed pregnancies the offspring is male. Lord Spencer found a pre- 

 ponderance of males between the two hundred and ninetieth and the 

 three hundredth days, but strangely enough all born after the three 

 hundredth day under his observation were females. It might be 

 reasonably inferred that while the prevailing tendency is to carry the 

 males overtime, yet that the smaller and comparatively much less devel- 

 oped female sometimes fails to stimulate the womb to contraction until 

 very far beyond the regular date. 



HYGIENE OF THE PREGNANT COW. 



Among domestic animals considerations of hygiene must be made 

 subservient to profit, and therefore the first consideration is not to 

 secure the most robust health, but such a measure of vigor and stamina 

 as is compatible with the most profitable utilization of the animal. The 

 breeding cow must earry a calf every year, and this notwithstanding 

 that she is at the same time suckling another large growing calf. The 

 dairy cow must breed every year, and at the same time must furnish 

 a generous flow of milk for from nine to eleven months yearly. If her 

 health is lowered thereby, or her life shortened, the question of profit 

 must still hold sway and she must yield her place to another when dis- 

 qualified. There are exceptions, of course, but this rule generally 

 holds. 



