INTERNAL SECRETIONS 85 



of distortion is extraordinarily heightened by hypertrophy of 

 the skin and the subcutaneous connective tissue. Ears, eye- 

 lids, nose, lips, fingers, are thick and heavy. The hair and nails 

 are coarse. The skin is folded, wrinkled, rough. 



The bodily ungainliness of a cretin has its counterpart in 

 the deformity of his mind. He is an idiot whose deficiency is 

 chiefly marked by apathy. 



Cretinism exhibits itself in varying degrees. The descrip- 

 tion that we have just given would not be accurate for all. 

 For the sake of brevity, we have chosen a case which might be 

 that of a goitrous cretin of a certain type, or that of a cretin 

 whose thyroid gland, in lieu of showing what looks like over- 

 growth, has failed to properly develop. Nothing is more 

 remarkable with regard to this organ than the fact that the 

 condition associated with its overgrowth and the effects of its 

 atrophy, or inadequate growth, are the same. A considera- 

 tion of the function of the gland will suggest an explanation 

 of this seeming paradox. 



The inconvenience caused by goitre induced surgeons, about 

 twenty-five years ago, to remove the tumour in simple un- 

 complicated cases. Owing to the accessibility of the gland, 

 the operation is both safe and easy ; but its removal was 

 found to be followed by symptoms of a very serious nature, 

 especially overgrowth and oedema of subcutaneous tissue, 

 muscular twitchings and convulsions, mental dulness. About 

 the same date, physicians recognized that the disease myx- 

 cedema so called because the oedema is not watery, as in 

 dropsy, but firm and jelly-like is due to deficiency of the 

 thyroid gland. 



No other organ of the body has so weird an influence upon 

 the well-being of the whole. No other organ has an equally 

 mysterious ancestral history. Assuredly the thyroid gland 

 was not always such as we see it now. In pre vertebrate 

 animals it must have been quite different, both in structure 

 and in function. From fishes upwards, however, its struc- 

 ture is always the same. It is composed of spherical vesicles 

 or globes. Every globe is lined by a single layer of cubical 

 epithelial cells. Its cavity is filled with a homogeneous semi- 

 solid substance known as " colloid." The globes are asso- 

 ciated into groups or lobules. They are in contact with large 



