Simple hyperplastic goiter was produced in young rabbits by feeding cabbage grown in England and which matured in the early summer. The cabbage was given over a period of 3 weeks in amounts equivalent to 75 calories per kgm. per day. Hay and whole oats prevented goiter. Cabbage which matured in the later summer during a period of drought was practically inactive. Simple hyper-plastic goiter was also produced in young rabbits, maintained on a diet of 35 gm. of rolled oats, 20 gm. of hay and distilled water, by the daily subcutaneous injection of 0.1 cc. of methyl cyanide for 21 days. Whole oats and London tap water prevented its occurrence. In attempting to produce thyroid hyperplasia by means of goitrogenic agents, it is essential that the animals'' diet is not antigoitrogenic. The relation between the production of thyroid hyperplasia by methyl cyanide and the Reid Hunt acetonitrile reaction is discussed.