the Relation of the Weight of the Contents of Stomach and Cecum to the Body-weight in Rabbits

In much of our experimental work upon mammals, the dosage of the various drugs used is regulated according to the size of the animal-a given amount being allowed per kilo of body-weight. In the rabbit this is a source of considerable error on account of the large size of the stomach and cecum. After a full feeding, when these organs have become well filled, the weight of their contents bears a relation to the total body-weight which is quite out of proportion to this same relation in other animals. In order to determine just how great an error would obtain from an inclusion of these contents in the body-weight of a living rabbit, I have removed and weighed the material found in the stomach and cecum in the case of fifty male and fifty female rabbits which were used in the laboratory for other purposes. In each case a record was kept of the sex, body-weight, weight of the stomach, weight of the stomach contents, weight of the cecum, weight of the cecum contents, and the number of hours the weight was taken after feeding. In removing the contents of the cecum an opening was made near the ileo-colic end, and by compression from the outside, everything was removed which could readily be expelled. Not more than three to five grams were ever left. None of the rabbits in my series were selected or fed beforehand in order to raise the percentage. Every rabbit that was killed in the laboratory was used until one hundred weights were obtained. Some had been