_The general method of operating_ is as follows: The incision is made between the last two ribs and in front of the thigh. The feathers over this region should be removed, and the skin pulled to one side before making the incision. An incision about one and one-half inches in length is made through the skin and muscles, and the spreader inserted. The sharp hook is then inserted and the thin serous membrane over the intestine is torn through. The testicles are situated in the superior portion of the abdominal cavity or under the back. On pushing the intestines to one side, both testicles, which are about the size of a bean and yellowish in color, can be seen. The lower one should be removed first. After removing both testicles, blood clots, feathers, or any foreign body that may have gotten into the wound should be picked up with the tweezers before removing the spreaders and allowing the wound to close. No special after-treatment is required. _The most common complication_ is rupture of the spermatic artery. This occurs at the time the testicle is torn loose and may be due to careless methods, or operating on cockerels that are too large. If all of the testicle is not removed from the abdominal cavity, the bird is termed a "slip." Sometimes air puffs form after the operation. These should be punctured with a sharp knife. OVARIOTOMY, "SPAYING."--The removal of the ovaries, or ovariotomy, is practised for the purpose of rendering the female more useful for meat production, prolonging the period of lactation, overcoming vicious habits and preventing oestrum or heat. The operation is commonly performed in the heifer and bitch, occasionally in the mare, and at present rarely in the sow. _Heifers_ are usually spayed between the ages of eight and twelve months; the _bitch_ and _sow_ when a few months old, or before the periods of heat have begun. The _mare_ is spayed when mature. It is possible to spay the female at any age, but the ages mentioned are the most convenient. Pregnant animals should not be operated on. The season of the year makes little difference in the results, providing the animal can be kept under close observation and given the necessary care and treatment. The spring of the year, just before turning the herd on pasture, is the best season to spay heifers. _All animals should be prepared_ for the operation by withholding all feed for at least twenty-four hours before they are operated on, and it may be advisable to give them a physic. It is easier to operate when the intestinal tract is comparatively empty, and the death rate is lower than when the animal is not properly prepared for the operation. _The method of operating_ is not the same in the different species. In young heifers and sows, the flank operation is preferred, and in mares and cows, the vaginal operation. The median line operation is practised in bitches. A spaying emasculator, or ecraseur, are the special instruments need for removing the ovaries.