_Fourth step._--The testicle, well enucleated from its superficial envelopes, but still covered by the fibrous coat, and the vaginal sac still remaining intact, the operator, facing, as before, the inguinal region, proceeds to the application of the clamps. The cutaneous covering and the dartos being pushed well upwards, the clamp is placed upon the cord above the epididymis, from before backwards, the assistant, armed with the castrating forceps, taking both of its branches between the jaws of that instrument, carefully bringing them together, and closing them as tightly as possible. The instant of the pressure of the clamp upon the cord is marked by very severe pain, and the suffering animal is excited to powerful struggling. It is important that the assistant should be aware of this, and he should be forewarned to refrain from pulling on the cord, and reminded, in order to avoid injury from this accident, to keep the clamps and the forceps steadily in contact with the inguinal canal. It is probably with a view to the avoidance of this possible injury that the use of a peculiarly constructed vise or forceps has been recommended. The forceps being in place, and tightly confining the branches of the clamps, well adjusted, the operator now applies the twine, and after taking several turns around the grooves of the free ends of the clamps, secures it carefully with a double knot. The operation is then repeated on the right or uppermost testicle in the same manner, and with the same precautions. UNCOVERED OPERATION. The four steps of this operation are the same as those of the previous method, the first requiring the same manipulations and observing the same order, but the second involving some variations. In this the same careful dissection is dispensed with, and one free incision suffices, including all the various envelopes, in order to expose the testicle freely and at once. The incision is made with one free stroke of the bistoury extending from the posterior to the anterior extremity of the testicle, and dividing at once scrotum, dartos, and the fibrous and serous coats. Though this is to be done without hesitation, it is by no means necessary to adopt the practice of some operators, who not only divide the envelopes, but even make a large incision in the testicular structure itself, inflicting thus an unnecessary amount of pain from which the animal might, with a little care, have been spared.