The observations and experiments here recorded have been made on dogs, and include three with normal, eight with colloid and seventeen with actively hyperplastic glands, as ascertained by the first specimen of thyroid removed. The plan followed has been to remove a control portion of the thyroid from each dog for histologic diagnosis and iodin determination, and at intervals to remove other portions for comparison.
Our experiments may be divided into two groups: (1) those in which iodin was administered and (2) those in which no iodin was administered, except what was contained in a liberal diet of cooked meat, bread, sodium chlorid, milk and water. The food being the same in each group, no other remarks are necessary, except that dogs normally store some iodin from such a diet. These two groups have been tabulated, and in presenting Tables 1 and 2 we have arranged the cases according