Let us recapitulate by defining the W-C Effect. When normal rats are injected with a single intraperitoneal dose of potassium iodide, in amounts 5 times or more greater than the total amounts of iodide measured in the thyroid gland of those rats, there is a complete blockage of organic binding of iodine, and by logical deduction, a complete blockage of thyroid hormone synthesis. This blockage persists as long as serum levels of inorganic iodide are maintained above 19 ug percent. However, under chronic conditions, when attempts are made to prolong the inhibition of organic binding of iodine in those rats by maintaining a high serum iodide levels, this inhibition persisted for 26 to 40 hours. After this period, the rat thyroid resumed its normal organification of iodine, in spite of the elevated serum iodide levels. Nevertheless, that did not prevent Doctor Wolff from implying that his third degree iodide excess with resultant W-C Effect, which he could not reproduce even in rats on a long term basis, probably occurs in humans.