Without entering upon the history which includes a record of the failures and successes attendant upon the introduction of the operation, it may suffice to say that until the improvements made by Charlier in the manipulations involved in the operation, it encountered considerable opposition, and it is within a comparatively recent period that it has become established in the domains of veterinary surgery. The indications by which this operation commend itself to agriculturists, and others who find profit or pleasure in the use or ownership of these domestic animals, are several. Among them are the influence which it exercises upon the secretion of milk in cows, and upon the power of accumulating fat, and its effects upon the character and temper of all the large females, in which relation it obviously acts as a therapeutic agent, in overcoming certain peculiar conditions by which they are distinguished. In respect to the effect of the operation of spaying the cow upon the milk secretion, it is a fact well established that it not only increases the amount and duration of the flow, but also improves the quality of that valuable fluid, the spayed cow not only continuing the production from eighteen to twenty-four months, but giving a product far richer in the elements of nutrition. This is shown by the enhanced proportions of the cream, the caseine and the sugar, which determine its richness and value, both economically and commercially, after alteration. But even this argument in favor of spaying the cow is rendered more weighty by the fact that besides its influence on the milky secretion, there is also that which is furnished by the consideration of its effect in augmenting the deposit of fat throughout the frame, for it is through this tendency that the flesh of the animal becomes so greatly improved in its nutritive quality as compared with that of the same species when in the entire condition, becoming so noticeably more tender, juicy and palatable, retaining more of the oily element, digesting more easily, and so, of course, acquiring a pecuniary value in the market not before possessed. These remarks apply to the dry equally with the milch cow, and leaving out the reference to the milk secretion, to the ox as well.