ABSTRACT
The skins of many vertebrates react to variations in the amount of hormones of the endocrine glands, especially of the thyroid and pituitary. Moulting in Triturus viridescens is inhibited after both thyroidectomy and hypophysectomy or both operations simultaneously performed. The cornified layers continue to form and the accumulation of these makes the animal appear grimy (Adams and Richards, 1929; Adams, Richards and Kuder, 1930; Adams, Kuder and Richards, 1932). The series of experiments here reported demonstrates that a similar effect occurs after hypophysectomy in immature or mature Triton cristatus (Adams, 1931a). The moult in Triturus viridescens operated in the above ways can be induced by various methods. Supplying thyroid hormone by thyroid grafts or thyroxin injections, or administering iodine to thyroidectomised or hypophysectomised animals or to ones lacking both glands, or stimulating the thyroid glands of hypophysectomised animals either by giving pars anterior grafts or injections or by pinching them in situ, will cause the shedding of the cornified layers (Adams et al. 1930, 1932; Adams, 1931 b, 1932). Similarly in hypophysectomised Triton cristatus, the moult can be induced by administration of pars anterior substance or by injection of certain extracts of mammalian anterior lobe.
For the preparation of “119,” see Wiesner and Crew, 1930, Proc. Roy. Soc. Edinburgh, 50, 79. In a personal communication to the author, Dr Wiesner describes the preparation of “192” and “196 C” as follows:
“Extract 192 is made in the following way: Anterior lobe is finely minced and boiled for a few minutes with 0·5 per cent, aqueous solution of acetic acid. Filter through paper. The filtrate is concentrated on a water-bath and adjusted to approximate neutrality with sodium bicarbonate. 10 c.c. corresponds to 2’0 gm. of fresh anterior lobe (beef pituitary).
“Extract 196 C is prepared in the following way: Extract 192 is deproteinised by addition of a small volume of 20 per cent, solution of sulphosalicylic acid. The proteins are rejected (centrifuged) while the supernatant liquid alone is used. Alcohol is added to the supernatant liquid until the precipitation of the alcohol-precipitable fraction is complete. The precipitate is well shaken with distilled water and the mixture is then centrifuged. The fraction which is insoluble in water and is obtained by centrifugation is taken up in 0 5 per cent, aqueous solution of acetic acid. This yields the ultimate extract which is adjusted with bicarbonate to approximate neutrality. 1·o c.c. corresponds to 2·0 gm. of fresh anterior lobe”
For the preparation of “198 E,” see Wiesner and Marshall, 1931., Quart. Journ. Exp. Physiol. 21, 147.
Grossly the thyroid of JH · 10 appeared to show slight stimulation but its cells had undergone some post-mortem disintegration and its interpretation was therefore doubtful.
See discussion in Adams et al. 1932, Journ. Exper. Zool. 63, 1.
