There are certain points, however, in which the interests of hygiene may be considered. The pregnant cow should have exercise, and as regards both exercise and feed, nothing is better than a run on a smooth pasture. She should be withheld from all violent excitement, hunting with dogs, riding or being ridden by cows in heat, driving in herd rapidly through narrow gateways, causing to jump ditches or fences, subjecting to blows with the horns of pugnacious cattle, driving on icy or otherwise slippery ground, carrying in railroad cars, kicking by vicious attendants, and fastening or throwing down for operations. The diet should be good, not of a kind to fatten, but with a generous quantity of nitrogenous constituents which will favor both the yield of milk and the nourishment of the fetus. Aliments like wheat bran, middlings, etc., which are rich in lime and phosphates, can be used to advantage, as there is a constant drain of earthy salts for the building of the body of the calf, and thereby the danger of undue concentration of the urine is lessened. Hard, innutritious, and indigestible aliments, musty grain or hay, partially ripened rye grass, millet, Hungarian grass, vetches, peas, or maize are objectionable, as they are liable to cause indigestion or even paralysis; and corn or hay affected by smut or ergot, or that has been spoiled by wet, overripened, and rendered fibrous and innutritious, is equally objectionable. In the main the feed should be laxative, as costiveness and straining are liable to cause abortion. Roots and green feed that have been frosted are objectionable, as being liable to cause indigestion, though in their fresh condition most wholesome and desirable. Ice-cold water should be avoided, as calculated to check the flow of milk, to derange digestion, and to cause abortion. A good temperature for the drink of the dairy cow is 55∞ F. In the case of plethoric and heavy-milking cows of mature age and in the prime of life, the hitherto liberal diet must be changed at the last week for the scantiest possible fare, and the bowels must be kept open by laxatives, if need be, if the owner would avoid milk fever. Her stall should not incline downward from shoulder to croup, lest the pressure of the abdominal organs should produce protrusion or abortion. She should be kept aloof from all causes of acute diseases, and all existing diseases should be remedied speedily and with as little excitement of the abdominal organs as possible. Strong purgatives and diuretics are to be especially avoided, unless it is in the very last days of gestation in very plethoric cows. PROTRUSION OF THE VAGINA (PROLAPSUS VAGIN∆).