Animal therapy is at this time an alluring subject, being unquestionably all in all the most revolutionary made in years toward the physiologic cure of disease. The medical profession should, figuratively speaking, bow its head in humble apology to the great physiologist and psychologist, Brown-Séquard, for when he contributed to his guild views which were the product of long years of delving and study, they were temporarily received with enthusiasm, but after only superficial consideration were laughed at as the product of a brain suffering from senile decay. We are now beginning to realize, as he did, that in the ductless glands lies the entire scheme of tissue building, repair, life. In this department of work the already established value of the thyroid gland in myxedema, obesity, idiocy, some forms of insanity and other conditions due to interrupted or misdirected metabolism is familiar to all, and favorable clinical evidence is