_Ligation of the cord and its envelopes._--This process is principally used upon small animals, although, since the elastic cord has been brought into use, a few attempts have been made to make it applicable to the larger kinds. The experiments, however, have been as yet so few, and the results so unsatisfactory, and in so many cases fatal, that it can scarcely be recommended, except for small subjects. The application of this is very simple. It consists, after securing the patient, in bringing the testicles as far down into the scrotum as may be thought needful, and after applying the ligature two or three times around the cord, a short distance above them (Fig. 14), slowly and steadily tightening it until a sufficient amount of force has been employed to close the calibre of the blood vessel and cut off the circulation from the parts situated below the point of ligation. This mode of operating has, in our hands, proved very successful in small animals, and when the elastic ligature has been used. Mortification has taken place in a few days, the testicles slowly detaching themselves at the point of ligature, and when falling off leaving but a very small superficial, cutaneous scab, and healing in a short time. [Illustration: FIG. 14. CASTRATION BY LIGATION OF THE CORD AND ENVELOPES.] _Ligature of the cord only; covered operation._--The first three steps of the operation having been accomplished, and the testicle enucleated, the ligature is placed around the cord, still covered by its fibrous envelopes and the cremaster muscle. A piece of twine or an elastic ligature may be employed for this purpose. In this operation the testicles are allowed to remain not less than twenty-four hours, before amputation is performed, in order that if the pressure has been insufficient, and the parts should fail to exhibit symptoms of loss of vitality after that time, another ligature may be applied. _Uncovered operation._--The only variation between this method and the one last considered is found in the fact that in this, the testicle and cord being exposed as in the process of castration with the clamp, the ligature is applied either on the cord as a whole, or only on its anterior fasciculus. In this case the testicle is amputated immediately after the application of the ligature. But as there is a possibility of the slipping off of the ligature, great care must be taken lest the amputation be performed too near the point where the constriction is made. And again, as there is a possibility of the truncated cord being drawn too far up, even up into the abdominal cavity, it becomes a precaution of prudence, as recommended by Mr. Bouley, to leave a sufficient length of the ligature hanging outside of the scrotal wound, and even to secure it on the edges of the skin.