_Causes._--In the new-born animal the opening of the navel is generally large, and may sometimes give way to the pressure of the bowel on account of the weak and relaxed condition of the abdominal muscles. This defective and abnormal condition of the umbilicus is frequently hereditary. It may be occasioned by roughly pulling away the umbilical cord; through kicks or blows on the belly; through any severe straining by which the sides of the navel are stretched apart. We may mention in this connection that it is best in new-born calves to tie the umbilical cord tightly about 2 inches from the navel, and then to leave it alone, when in most cases it will drop off in a few days, leaving the navel closed. _Treatment._--It is well to bear in mind that many, and especially the smaller, umbilical hernias heal spontaneously; that is, nature effects a cure. As the animal gets older the abdominal muscles get stronger and possess more power of resistance to pressure, the bowels become larger and do not pass so readily through a small opening, so that from a combination of causes there is a gradual growing together or adhesion of the sides of the navel. In cases of umbilical hernia in which there are no indications that a spontaneous cure will take place, the calf should be laid on its back; immediately on this being done the hernia will often disappear into the abdomen. If it does not, its reduction may be brought about by gentle handling, endeavoring, if need be, to empty the organs forming the hernia before returning them into the abdomen. After the hernia has been returned, the hair should be clipped from the skin covering it and a compress composed of 10 or 12 folds of linen or cotton should be applied, first smearing the skin with pitch and then a bandage about 3 inches wide should be passed round the body so as to retain the compress in position. The lower part of the compress should be smeared with pitch, and also those portions of the bandage which pass over it, so as to keep it solid and prevent it from shifting. In some cases it will be found that the contents of the sac can not be returned into the abdomen, and this generally arises from the fact that some part of the contents of the sac has grown to or become adherent to the edges of the umbilical opening. In such a case the skin must be carefully laid open in the long direction, the adhesions of the protruding organs carefully separated from the umbilicus, and after the protruding parts have been returned into the abdomen, the sides of the umbilicus must be freshened if necessary by paring, and then the edges of the opening brought together by catgut stitches; the wound in the skin must then also be brought together by stitches. The wound must be carefully dressed every day and a bandage passed round the body so as to cover and protect the part operated on.