Carrel in 1914 reported a strain of connective tissue that had undergone 358 passages and had then reached the twenty-eighth month of its life _in vitro_. It was detached from the heart of a chick embryo seven days of age, which pulsated for 104 days and gave rise to a large number of connective tissue cells. These multiplied actively for the first two years, a great many cultures having been derived from this strain every week. The fragment of the tissue usually doubled in forty-eight hours, though rapidity of growth was subject to fluctuations. One striking result is seen by comparing the amount of tissue produced by a given culture in forty-eight hours this year with that produced in the same tissue by the same strain of cells a year before. This shows that the activity of the strain had increased, although this might, of course, be due to improvement of technic or possibly to a progressive adaptation to life _in vitro_. Carrel says: “Thus it is conclusively shown that the proliferating power of the strain has in no wise diminished. During the third year of independent life, the connective tissue shows greater activity than at the beginning of the period and is no longer subject to the influence of time. If we exclude accident, the connective tissue cells, like infusoria, may proliferate indefinitely.” In the latest report at hand one of these cultures had been kept alive and growing thus for seven and a half years. * * * * * The original and indefatigable American-Frenchman, C. E. Brown-Séquard (1817–1894) who in 1878 succeeded Claude Bernard in the chair of experimental medicine in the _Collège de France_, was one of the first experimental physiologists to study the functions of glands and to realize the importance of their secretions. After investigating the suprarenals in animals as early as 1869 and finding that their removal always caused death, he returned to this subject twenty years later to investigate the testicular fluids which, discharged into the blood, “exalted the power of the nervous system and kept up the vital energies.” He even injected the fluids extracted from the testes of animals into his own system hypodermically, with results that he thought distinctly beneficial to himself and says that he “at the age of seventy recovered the force and energy of youth, with manifestations unknown for a number of years.” He thus believed that he had discovered a new therapeutic agent of great rejuvenating power. Berthelot says, “The subject required delicate manipulation, not only because of the extraordinary precautions required for this kind of investigation but of charlatanism, always ready to possess itself of new curative procedures. He did not protest against the abuses by which his name was used to cover industrial enterprises.” He persisted in his idea, and he, more than anyone else, should be called the founder of opotherapy or treatment by extracts from organs. His name will