The Relation of the Gastro-intestinal Tract and Contents to the Body-weight in Rabbits

In some experimental work on rabbits in this laboratory, in which the results were based on the bodyweight , it has been found necessary to avoid the error introduced by the variation in the weight of intestinal, stomach, and bladder contents. In view of a possible wider interest in the data collected for our use, we report them in this paper. Joseph I examined one hundred rabbits for the purpose of determining the proportion of bodyweight which should be allowed for stomach and cecum contents when the dosage of various drugs is based on the weight of the animal. He gives figures for stomach and cecum contents of males and females, and for the stomach and cecum minus contents. The results given in this paper deal collectively with the contents of the stomach, small intestine, cecum, large intestine, and rectum, of both sexes; the figures also include the weights of the organs after the contents had been removed, in normal, castrated, and thyroidectomized animals. The data in the literature upon this subject are not sufficiently complete to meet all conditions nor to justify the formation of a rule which will cover all cases ; hence it became necessary to determine the exact weights in each animal used. The error in body weight due to bladder contents may be obviated by applying digital pressure on the abdomen in the region of the bladder as soon as the animal is dead and the muscles are relaxed. This method was used in every case, and throughout the paper the weight after removal of urine is spoken of as gross bodyweight. The problem of eliminating the error