If the clamps have been secured with twine, and especially if they were properly prepared previously to their application, the process of removal is a very simple one. The assistant, raising one of the patient’s hind legs, the operator places himself directly behind the animal, and bending down, with a sharp sage-knife, cuts the twine where it has secured the posterior ends of the clamp. If it retains the springiness it ought to have possessed at the time of its original application, the branches readily spring open, and it falls to the ground. If this does not occur, or if they should be held by adhesions with some dried parts of the cords which have been pressed between the branches of the clamps, they must be carefully separated by moving from below upwards, when they will easily become detached. But this last manipulation must be very carefully performed, if we would escape a hemorrhage which might require serious measures to control. When clamps of another make are used, the process of removal will vary according to existing peculiarities in the construction of the instrument. The clamp having been removed from one side, the separation from the other will, of course, be managed in a similar manner. THE LIGATURE. This method of castration consists in the application of a circular ligature upon the entire cord, or a portion of it, for the purpose of completely closing it, with the various parts entering into its formation. It was in practice so long ago as 1734. The operation is divided into several varieties, viz., that of the cord with its envelopes; that of the cord only, either by the covered or uncovered method; that of the spermatic artery alone; that of the efferent canal; and that by the subcutaneous process. The ligature used in these various modes of operation is formed of waxed silk; sometimes of strong twine, as fishing line, for example; or, as more recently introduced in surgery in the removal of living growths and tumors, an elastic cord.