6
1574 (a)—four years before Harvey was bom, and fifty-four years before the publication of Harvey's great work, De motu cordis et sanguinis; yet no one during that long period anticipated the discovery of the circulation, and so little were anatomists prepared for it, that its truth was but slowly admitted, and among its opponents were such men as Gaspard Hoffman, Gassendi and Riolan (b).
To us of the present day, to whom the circulation of the blood is a familiar fact, the action of the valves in the veins may appear very suggestive, or sufficient, evidence; but assuredly it was not sufficient for Fabricius and the other great anatomists of that time. Indeed we must try to put ourselves in their place, if we would form a just estimate of the intellectual merits of Harvey's discovery or even of the steps by which he reached it. We must remember how utterly erroneous were the notions then prevalent as to the functions of the heart, arteries and veins. We must remember that the heart had not been recognised as a propeller of the blood; that its substance was not known to be muscular; that its movements and those of its auricles and ventricles had not
