A short review of the history related to the identification and classification of cardiac hormones shows that long before the development of modern scientific technology these substances had been predicted. It is an outstanding example of how meticulous observation, even with simple instruments, coupled with creative imagination, sound logic, and far reaching vision, may bring about marvelous accomplishments. The fast changing field and numerous contributions are responsible for the unsettled nomenclature and not completely settled concepts of the heart as a pump and as an endocrine organ. Although the bulk of knowledge amassed prior to the advent of the electron microscope is amazing, it was, however, only after the biological application of electron microscopy that the morphological evidence of the cardiac elements responsible for the endocrine function of the heart could have been provided. As usual, although not always the case, it was the anatomical, specifically the subcellular, description of the endocrine cardiomyocytes that caused the recent extraordinary advances in the recognition of another function of the heart. In a broad sense, the extension of internal secretion and its subcellular morphological background to other structures allow one to add endocrinosity as a general principle of construction and function of the human body. Our selective, obviously incomplete review, may not include publications that a different subjective approach might have included. While the Authors count on the indulgence of the readers, they emphasize that what is missing is not necessarily less important. The main aims of this publication have been to concentrate on early historical developments and to be able to repeat, once again, how much the mind can accomplish, even without the wonders of modern technology. Once the latter is made available, however, it obliges scientists to use their ingenuity at a higher level, providing the scientific and technological revolutions that occur from time-to-time. The recent history of medicine is replete with such events, which have proven so beneficial for mankind.