288 THE DUCTLESS GLANDS 



cold. In later stages of the disease perspiration may be entirely 

 absent. Warts and moles may occur. 



The hair becomes thin and scanty. In some cases the head 

 is almost completely bald, and the skin of the scalp becomes 

 dry, brown, and scaly. The teeth often become brittle and 

 carious. The mucous membranes may be swollen, and there 

 is dryness in the mouth and nose. In fully developed cases 

 the temperature is almost continuously one, two, or three 

 degrees below normal. Mental dulness, drowsiness, and slow- 

 ness of reaction are characteristic of most marked cases. There 

 may be hallucinations going on to definite insanity. Sight, 

 hearing, taste, and smell are often more or less impaired, and 

 sexual feeling may be diminished. 



We shall see later on (p. 289) how far these symptoms corre- 

 spond with those observed in human beings after operations 

 upon the thyroid, and in animals after experimental thyroidec- 

 tomy (p. 300). 



(6) Morbid Anatomy. The most interesting changes are 

 found in the thyroid lobes. The Myxcedema Committee in 

 1858 found that out of fifteen cases in which the thyroid was 

 examined post mortem, there were six of atrophy of the glands, 

 and all were diminished in size, of a pale yellowish-white colour, 

 hard, and fibrous. There was a connective-tissue overgrowth 

 which led to a destruction of the parenchyma. At the same 

 time there was a new formation of lymphatic tissue. 



Similar conditions have been reported by other observers. 

 The cells of the vesicles are reduced in number, and their nuclei 

 in staining capacity. The intervesicular tissue is cedematous 

 and poor in nuclei and in fibrils. 



The pathological process consists of a very slowly progressive 

 atrophy. In most cases this seems not to be the result of 

 ordinary inflammatory processes, though Ponfick records 

 diminution in size of the thyroid as a result of a violent inter- 

 stitial inflammation. Even when the thyroid is increased 

 in dimensions, as occasionally happens, the vesicular substance 

 has for the most part disappeared, and its place has been taken 

 by interstitial growth. 



In the skin the connective tissue of the corium has its ele- 

 ments torn asunder. The fibres are hyperplastic. The cell 

 nuclei and the fibrils of the gelatinous substance between 

 the fat lobules are multiplied. The whole 1is>u< lias a trans- 



