Origin and control of the light cells in the thyroid gland of the rat.

The first description of the microscopic anatomy of the thyroid gland was given by Lalouette (1750) who described it as being composed of inter-communicating vesicles. However from time to time controversies arose over different aspects of thyroid histology. Jones (1852) and more recently other workers (Bargmann, 1939; Maximow and Bloom, 1957; etc.) described the thyroid gland as being covered with a connective tissue capsule from which septa penetrated the gland and divided it into well-defined lobules. Bichat (1823) and others (Wegelin, 1926, etc.) failed to observe the limits of the lobules distinctly