In relation to this latter object it must be borne in mind that the operation is followed by certain peculiar effects, which may either manifest themselves upon the entire organism, or upon some special functions only. In the first instance it is quite evident that the primary and most obvious effect of the mutilation is to be discovered in the character and disposition of the animal, which at once becomes in a double sense an “altered” creature, docile and submissive, and entirely willing to become the obedient and useful servant of his human master. But it is not alone that we find the vicious stallion, the uncontrollable bull, the kicking jackass, the dangerous boar, and even the hysteric mare and cow transformed into the useful gelding, the quiet ox, the patient donkey, and the “fatherly” barrow, the quiet working mare and the productive cow, as the result of the change which the character--the nervous system, in fact--has undergone. Besides this, other marked changes are to be observed of a more distinctly physical character, such as a modification of the entire organism, manifested in the external symmetry, and the expressive physiognomy of the creature, when deprived of its virility. The animal becomes more quiet, and its general form is modified. If altered at an early age, the skeleton will be arrested in its growth, and the mass of muscles attached to it will participate in the defective development; the head will become elongated, the legs will continue to be lighter, and the body will show a corresponding lack of development. In other words, the male animal will tend to assume the characters of the female, in form and feature, the gelding, indeed, resembling the mare, not only in the _ensemble_ of his appearance, but in his voice, which loses the resonance of the stallion’s, and his physiognomy, which becomes milder and less expressive; while his neck is lighter and his mane more scanty, with the hairs which compose it more fine and silky. A like tendency exists in other male animals to acquire a resemblance to the female as an effect of the operation of castration. The altered bull has a weak and feminine voice; his head is narrower and elongated; his horns become lengthened and more curved; he has exchanged his wild and threatening aspect for a mild and gentle visage; his neck also is lighter and his chest narrower; his bony structure is less massive; and he has, besides all the rest, acquired a quality of essential importance to mankind in a dietetic view, that of accumulating fat. This last phenomenon shows us that besides the other changes referred to, there is an important modification of the nutritive forces of the animal, or at least a change in the direction of their action.