In the _female_, when, as is sometimes supposed, it becomes a preventive measure in respect to hydrophobia--though if it be so, it can only be from the fact that a castrated bitch will usually remain at home while others are running abroad in heat, and thus being more exposed to contagion--the operation is only justifiable in the case of house dogs, domestic pets, in order to obviate the annoyance caused to their owners by their demonstrations while in heat. In the bitch the broad ligaments are very long (Fig. 43), extending as far as the hypochondriac region, where they divide into an external layer, which reaches to the last rib, while the other extends to the sub-lumbar region behind the diaphragm. The broad ligaments diminish in height as they run forward in such a way that the anterior border of the external layer where the ovary is found, shorter in its median part, gives a certain amount of fixity to the anterior extremity of the horns which it keeps elevated in each hypochondriac region; on that account both horns cannot be at one time brought through the incision, and it becomes generally necessary in the bitch to operate on each side. The manipulations are similar to those followed in spaying sows, with the exception that the incision is made lower, more forward and nearer to the last rib. CASTRATION OF FOWLS. The effect of this operation upon the quality of the flesh and the power of accumulating fat, in the domestic fowl is a fact too familiar to those who have learned to appreciate the exquisite juicy quality of the meat of the capon to need any comment at our hands. The operation upon these animals is one of considerable difficulty and requires skill and experience to perform with nicety and success. In birds the testicles are situated in the abdominal cavity, immediately behind the lungs, under the vertebral column and in front of the kidneys (Fig. 44). They correspond exactly to the articulation of the last three ribs with the spinal column, where they lie close together and in contact with the blood vessels which separate them from the kidneys. They are held in position by the peritoneum spread above them, and by minute blood vessels, branches of the aorta or of the vena cava. [Illustration: FIG. 44. GENITAL ORGAN OF THE ROOSTER. 1.--Testicle. 2a, 2d.--Deferent canals. 3.--Ureters. 4.--Cloacum. 5.--Posterior aorta. 7.--Posterior vena cava. 8, 9, 10.--Three last ribs. 11.--Pelvic bones.]