THE DUCTLESS GLANDS 1327 



as myxoedema with atrophy of the thyroid. A patient affected with 

 niyxffidema presents a gradually increasing blunting of his or her 

 mental activities ; speech is slow, cerebration delayed. With this 

 nervous defect are associated changes in the connective tissues, 

 the subcutaneous connective tissue becoming thickened, so that 

 the face and hands appear swollen and puffy, looking at first 

 sight as if oedema were present. The swelling is, however, due 

 to newly formed connective tissue, and not to the presence of 

 an excess of interstitial fluid in the tissues. The patient often 

 presents a yellow, waxy appearance with a patch of colour on the 

 cheeks. The hair falls out, the pulse is slowed, and the temperature 

 tends to be subnormal owing to the diminution of the rate of meta- 

 bolism in the body. The intake of food and the excretion of urea are 

 diminished. If the atrophy of the thyroid occurs in early life during 

 the period of growth, e.g. in young children, the growth of the skeleton 

 practically ceases. The bones of the limbs may grow in thickness but 

 not in length. There is early synostosis of the bones of the skull, 

 and complete cessation of development of mental powers. Children 

 so affected may live for many years, but when twenty-five or thirty 

 present still a childish appearance (Fig. 545, c). Stunted, pot-bellied, 

 and ugly, they have the intelligence of a child of four or five. They often 

 present fatty tumours above each clavicle, and similar subcutaneous 

 tumours of fat or loose fibrous tissue are found in cases of myxoedema 

 in the adult. 



When the thyroid is extirpated in man the result is often the 

 production of typical myxcedema. In some cases, especially in young- 

 individuals, the results are more severe, a condition of tetany being 

 set up in which there are tonic spasms of the muscles of the body, 

 especially of the extremities. When the thyroid gland is extirpated 

 in animals the results more closely resemble these acute cases. In 

 certain cases a chronic condition of malnutrition is set up, but a 

 typical myxoedema with thickening of the subcutaneous tissues by 

 new growth of connective tissue has only been described by Horsley 

 in monkeys. The effects are more pronounced in carnivora than in 

 herbivora. In the former a condition of tetany is produced accom- 

 panied with muscular tremors and clonic convulsions which come on 

 at intervals and may be accompanied with severe dyspnoea leading 

 to death within fourteen days. In herbivora, wasting, diminution of 

 respiratory exchange, and disorders of nutrition are often the most 

 prominent symptoms. These results have been ascribed by Munk 

 to interference with the recurrent laryngeal nerves during the 

 operations, but the observations on man leave very little doubt that 

 they are due entirely to the removal of the chemical influence of the 

 thyroid gland. Many authorities were at first inclined to ascribe 



