The third step, or that of the torsion of the cord, now presents itself to our notice. To effect this, the testicle must be firmly held at the bottom of the envelopes (Fig. 19), the left hand placed forward upon the cord, and the right behind and upon the testicle. The operator then gives to the organ a twist with the right hand by a motion of rotation from left to right and from without inwards, while with the other he draws upon the cord in the opposite direction. The result of this manipulation is to give to the gland half a turn around the cord (Fig. 20), which thus becomes displaced and takes a posterior position. By a change in the action of the hands, but a repetition of the same movement, the right hand now acting on the cord, while the left is applied to the testicle, the remaining portion of the motion of rotation is performed, and a complete torsion of the spermatic support accomplished. By repeating this action, of course as many turns of the cord as may be thought necessary, can be secured, two, however, being generally found sufficient, although, in a few instances as many as four or five may be required--never more than that. The length of the cord is the principal controlling circumstance. When these several steps have been completed with one testicle, their repetition is, of course, in order with the other. And when both have been treated, the consummation of the operation is called for by entering upon the fourth step, or that of the application of the ligature. [Illustration: FIG. 21. DOUBLE SUBCUTANEOUS TORSION IN CATTLE. Position of the testicles and ligature en masse of the bags when the operation is finished.] To accomplish this both testicles are firmly seized with both hands, and pressed upwards as far as possible against the inguinal ring (Fig. 21). It is necessary to be very careful to ascertain that they rest on the same level, in order to be secure against the possibility of untwisting. The ligature is then applied by passing three or four turns of it around the scrotal envelopes, immediately below the testicles, with not more than a sufficient degree of tightness to assure it against slipping off. The symptoms which succeed the operation are not commonly of a very serious nature, and subside within a period of time varying from two to six hours. Following the operation an inflammatory swelling takes place in the bags, and after one or two days assumes large dimensions. The ligature can now be removed, and the animal left to himself, without further treatment, the testicles undergoing a slow process of atrophy readily recognized by their appearance and the position they always thereafter occupy in the vaginal sac. CASTRATION OF CRIPTORCHIDS.