Among the effects of thyroidectomy obscrvcd by the early investigators were alterations in the anterior pituitary gland. Accurate cytological description awaited the study of the goat by Trautmann ( '16) and the publication of pliotoniicrographs of the thyroidectomy cells of the rat by Rojima ('17).
Experiments aimed at determining which type of normal pituitary cell gives rise to the thyroidectomy cell were Iianipercd at first by the lack of adequate cytological methods.
Thyroidectoniy cells were held to be essentially like castration cells by Severinghaus, Smclser and Clark ('34) and by Severinghaus ( '38) while the difference between thcrn were emphasized by Zeckwei-, Davison, Kcllcr and 1,ivingoocl ( '3t5),
Zeckwer ( '37) and Reese, Koneff and Wainniaii ( '43).
The modern aspects of the prolnleni of thyroidectomy cell origin date from the introduction of histochemical methods into pituitary cytology. Following a lead supplied by Goniori ( '50)' aldehyde fuchsin was found by Halnii ( '50) to be a specific stain for the beta cells of Romeis ('40). The term "tliyrotroph" was suggested a s a descriptive name for this cell by Purves and Griesbach ( '?la, b) on the basis of evidence that it is the source of thyroid stimnlatiiig hormone.
Ability to distinguish thyrotrophs from gonaclotrophs and thyroidectomy cells from castration cells did not provide an unequivocal solution to the problem of tliyroidectoniy cell