Microscopic Changes Induced in Thyroid Gland by Oral Administration of Desiccated Thyroid

The first demonstration of the effect of a substance from outside the body on the microscopic structure of the thyroid gland was the deposition of colloid within the follicles of the thyroid gland of the dog after the administration of iodine, reported by des Ligneris¹in 1907 and by Marine and his co-workers²in 1908. Since these early observations there have appeared in the literature from time to time controversial reports regarding the effects of iodine and other substances on the normal thyroid as well as on certain types of enlargement of the gland, (Loeb³and others3a). It would be aside from the purpose of this paper to attempt a critical résumé of the vast literature on this subject up to the present, for, although there have been many and important contributions to knowledge of enlargement of the thyroid gland, the cause and method of prevention