Page:The Harveian oration 1903.djvu/63

THE HARVEIAN ORATION, 1903 57

the muscle or nerve-fibre and of the gland-cell awaits solution. Though it may be true that “it is quite impossible to attain to a complete knowledge of function without a thorough anatomical analysis” (Huxley), and this it may be added although the observation of function may have led to the study of structure, yet it is clear that “structure” must include a wider range of meaning than hitherto it has been commonly thought to bear, and to reach into those regions where observation is conditioned by speculation and where theory has to take the place of demonstrable fact. However true it may be that for a general conception of the physics of the circulation Harvey was beholden to his anatomical knowledge, it is also true that for our later acquired information of the share taken in the movement of the blood by the arteries an acquaintance with the structure of these vessels is necessary, whereby their elasticity and their tone are referred each to its own tissue. ‘The problem that Harvey solved was one that in its broad features was a mechanical one; but it does not end with such information as the gross anatomy of the organs and the histology of the tissues supply. Behind it lie the contraction of the muscular substance of the heart and arteries and the nervous governance of that material, which involve considerations of another character.