I have quoted only two out of many similar cases. However, apart from surgical evidence, there exists proof of the uselessness of the large intestine in man. The best argument in favour of the proposition may be drawn from the case of a woman who for thirty-seven years discharged the waste matter from the alimentary canal through an intestinal fistula. The latter had opened spontaneously, as the result of an abscess seated on the right side of the abdomen. Her complaint, however, had not prevented her from marrying, from bearing three children, nor from pursuing an arduous calling. The person in question, who was a workwoman in Varsovie, was examined by a surgeon, M. Ciechomski,[80] thirty-five years after the establishment of the fistula. The surgeon proposed to operate, hoping to restore her to the normal condition, and the woman consented. However, when the abdominal cavity was opened, it appeared that the large intestine had atrophied along the whole length, from the cæcum to the rectum; the inner orifice of the fistula had passed into the digestive tract above the cæcum, opening into the small intestine. In the circumstances it was impossible to close the fistula, and the surgeon had to close up the abdominal wall, leaving the patient in her former condition. The woman recovered rapidly, and continued her usual mode of life. She came under observation again two years later, but since then had been lost sight of. The fact that a human being was capable of carrying on an apparently normal life for thirty years in the absence of a large intestine is good proof that the organ in question is not necessary to man, although it has not yet become rudimentary. In this case again, to find the useful stage of the structure, we have to go to our remote ancestors. The large intestine is much better developed in most herbivorous mammals than it is in carnivorous forms. Although it is useless in the digestion of animal food, it has an undisputed importance in the digestion of vegetable matter. It has a very large calibre in herbivorous creatures, and the voluminous cavity contains quantities of microbes which are able to digest cellulose. As cellulose is a material that resists the ordinary processes of digestion, it is easy to see the advantage derived from the harbouring of the microbes. It is more than probable that in the horse, the rabbit, and in some other mammals, that live exclusively on grain and herbage, the large intestine is necessary for normal life. On the other hand, the large intestine discharges a function similar to that of the urinary bladder. The urine, which is being secreted continuously by the kidneys, accumulates in the large reservoir provided by the bladder. Similarly the waste matter from the processes of digestion accumulate in the large intestine and remain there for a longer or shorter period.