In 1916, Graham1 applied the Gudernatsch test to goitrous material of various kinds and showed that a certain definite relationship exists between the iodine and colloid content and the physiologic activity of tadpoles on which the test is made. Since then a great number of similar experiments have been carried out in different countries on every kind of goiter. Particular reference might be made to the work of Wegelin and I. Abelin,2 of C. Abelin,3 and of Branovaĉky4 on normal and abnormal human thyroid glands of all clinical and histologic groups; of Wydler5 and of Dubois6 on the goiters of cretins, and of Branovaĉky and Pelech7 on certain malignant goiters. In 1923, Hara8 applied the Asher-Streuli test on rats to different types of goiter.
His findings were confirmed and extended by Branovaĉky.9 The conclusions drawn from those investigations of the Bern school were that only within one of the