Summarizing the details of this observation, we can say: 1 Improvement is manifested first by a rise in the patient’s temperature, a rise of one degree on average, after the operation. This rise in temperature cannot be due to a post-operative febrile reaction. The general state of the patient was excellent, no discomfort, no shivering, and, above all, regularity of the temperature. 2 The red blood cell count rose rapidly and progressively over the course of a month. From 2,449,000 it rose to 4,247,000, almost normal. 3 All movements became less slow and easier, and speech became less slow and less indistinct. 4 Perspiration, which had completely disappeared, returned after the operation. Feelings of cold, particularly on the back, about which the patient complained repeatedly, ceased completely. 5 The swelling of the body seemed to lessen, in that the patient now wore clothes and shoes which she had not been able to wear for a long time. 6 After the operation, menstruation, which had never lasted less than fifteen days (sometimes three weeks) before the operation, lasted scarcely four days. 7 The weight of the patient had fallen notably: from 119.5 kg it fell to 113.8 kg. The results are thus, until today, very encouraging. But does this allow us to conclude that the transplant has been a complete success, that is to say the full complete vascularisation of the two glands introduced into the patient’s tissues? Certainly not. The improvements observed manifested themselves on the day after the operation, so it is more logical to attribute them to the simple absorption by the patient’s tissues of the thyroid gland ‘juice’. It is for this reason that with another patient with myxœdema currently at the “Maison de santé” we are proposing to try hypodermic injections of glandular ‘juice’.