“…Many of the conclusions s upon results obtained after removing the thyroid or mm adrenal glands which may be a rather crude technique (Astwood, 1957), and some of them may have P'glet ,kept been confused by the effects of restraint (Bartlett, Bohr and Inman, 1955;Hahn and Koldovsky, 1958b). Full temperature control is not acquired till the animals are about 26 days old.…”