THE DUCTLESS GLANDS 1239 



and not to the presence of an excess of interstitial fluid in the tissues. The 

 patient often has 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 metabolism 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 develop- 

 ment of mental powers. Children so affected may live for many years, but 

 when twenty-five or thirty present still a childish appearance (Fig. 560, 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 instances 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 been described by Horsley only in 

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

 In the former a condition of tetany is produced, accompanied 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 were 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 these results in man and animals to the circulation in the blood of 

 toxic substances which would normally undergo destruction in the thyroid 

 gland. This theory is put out of court by the results of administration of 

 thyroid gland to patients with myxoedema or to animals deprived of their 

 thyroids. Schiff first showed that the effects of extirpation of the thyroid 

 might be prevented if, at the same time, the thyroid from another animal 

 were transplanted into the subcutaneous tissue to take the place of the one 

 removed. On removing the transplanted thyroid, the typical symptoms 

 of thyroid destruction at once ensued. It was later found that similar 

 good results could be obtained by subcutaneous injection of the expressed 

 juice of the thyroid, and later that even this was not necessary, -and that it 

 was sufficient to administer the thyroid gland, either fresh, dried, or partially 

 cooked, by the mouth. The administration of the thyroid gland in this way 



